Precession – work in the pipeline

It is common for composers to consider their work through a number of dimensions or axes; examples of which can be found in fugue technique, Whishart’s lattice model (Wishart, 2002) or more extremely, embodied throughout the methodology of 12 tone serialism (Schoenberg and Stein, 1950).

This planar thinking lends itself to the invention of various compositional techniques, on a simplistic level running variables in in retrograde fashion through to the nested recursion of the Art of Fugue (Bach, 1750) and Markov Chain compositional techniques (Roads, 2000). This is often linear, looking at a set of pitches or rhythms; interrogating and manipulating a stream of data points. From there it is only a small step to link extra information to this data. For instance, at a given time a certain note could be played at a specified volume by a given instrument (Boulez, Cage and Nattiez, 1999). Thus, in computing terms we arrive at a two-dimensional array of data, something potentially very close to a square if you were to tabulate it.

With the addition of other data and relationships comes the opportunity for higher dimensions within this array, popping an extra axis into a cube, followed by a tesseract, up until such points as it would be difficult to perceive within an audible work.

What if, rather than dealing with data points the composer was able to manipulate the dimensional space of the larger work?

Precession is an exploration of these ideas. It draws on the Pitch Volume Timbre space defined by Wishart but folds in one side of the ‘cube’ to form a pyramid space. Working from the assumption that pitch is mapped to x volume to y and timbre to z notes can be placed anywhere within the body of the pyramid. This simple translation brings a deal of creative perturbation to the system, as when any datum is near the apex of the pyramid (z axis) its potential placement within the two remaining axes (x,y) across the square base are several limited.

Where this becomes especially interesting is being able to roll the pyramid like a die within compositional space. If the view point remains fixed with x for pitch etc. any movement of the pyramid re-voices the notes therein, potentially in strikingly different ways. Thus, phrases are cast and re-cast within the rolling die of the shape causing processionary transformations of the material.

Instrument design realised in Supercollider

Visual components and data transformation in Processing

Composition and array transformations Excel

System communication OSC

Edward Wright 3/12/19

Bibliography:

Bach, J.S. (2013). The Art of the Fugue & A Musical Offering. Composed c. 1740-50. Newburyport: Dover Publications.

Boulez, P., Cage, J. and Nattiez, J. (1999). The Boulez-Cage correspondence. Cambridge [England]: Cambridge University Press.

Roads, C. (2000). The computer music tutorial. Estados Unidos: The MIT Press.

Schoenberg, A. and Stein, L. (1985). Style and idea. First published 1950. Berkeley: University of California Press.

Wishart, T. (2002). On sonic art. London: Routledge.

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Turbo, Maths and Music

I have already written about some of the creative aspects of Turbo, the piece of music I am currently working on here https://edvirtual440.wordpress.com/2019/07/22/turbo/, but following interest from a number of people here is a bit of a deeper dive into the mathematics of the piece.

Under the gloss and shine of the main body of the work there is a continuous recording of a Ferrari 412 T2 F1 car. The recording starts played back very slowly; gradually getting quicker until it is at normal (breakneck!) speed at the end.
Artistically this was done to draw the listener in, there is a slow but impending inexorability about it but I wanted it to work creatively as more than just a cheap trick.

The playback speed is modelled on a golden spiral (i.e. a logarithmic spiral whose growth factor is φ the golden ratio) a design found not only in some engine turbos but also the humble snail from which the component took its name.

A golden spiral with initial radius 1 has the following polar equation:

If one were to travel inwards on such a spiral at a constant speed the time it would take to describe a full rotation around the centre decreases. While your speed would stay the same, in terms of RPM you would be accelerating. The manipulated Ferrari recording follows this pattern making 3 full rotations of the spiral appearing to get faster towards the epicentre at the end of the piece.

At a simple level digital audio works a lot like animation. A snapshot of a soundwave is taken numerous times a second (44100 for CD quality) and these snapshots are essentially then played back in order to create a close likeness to the original continuous sound. Just like animation and flip-books you can change how fast you leaf through the individual ‘pages’, and thus gain mastery of speeding up, slowing down or even appearing to reverse time.

The piece of music was to be 8 mins 39 seconds long. I wanted the Ferrari to be at normal playback speed at 8:38. Hence it was a task of mapping the sample rate to time or its equivalent distance along the spiral. Looking at it backwards I was aiming for a sampling rate of 44100 Hz at 8:38 with that rate decreasing by the proportions of the golden spiral as the time elapsed from the beginning of the piece of music trended to 0. 

Several cups of tea later I came up with the following which gives sample rate (Hz) relative to time (s). This is copied from the code which I had left deliberately un-simplified so that I could still almost see what I was doing!

Sample rate =44100(1/(pow(((1+sqrt(5))/2),((LOG(1-((1-pow((1+sqrt(5))/2,(12)))/(1-(1+sqrt(5))/2)-TIME)+(((1+sqrt(5))/2)*((1-pow((1+sqrt(5))/2,(12)))/(1-(1+sqrt(5))/2)-TIME))))/(log((1+sqrt(5))/2)))-1)))

This resulted in a gradual and inevitable winding up of speed but was still very ugly not to mention the processing power it drew before even handling audio. It turns out that trying to feed a digital-analogue converter floating values for sample rate (as opposed to integers) is not a great idea and leads to clicks and glitches. This brought down my need for fine grained resolution by a significant factor. In addition the difference of +/- of half sample is inaudible when 44100 are going past in a second! 

This meant that rather than calculate it all on the fly I stuck the formula into and excel spreadsheet and told it to calculate relative to the rows while rounding to the nearest integer; hence an instant lookup table with a revised sample rate for every second. Incidentally it started off *really* slowly at 221 samples in the first second!

I then cooked up a simple playback and record program (it has had 2 incarnations, being initially built in MAX/Msp and later Supercollider due to cross platform issues). It takes the excel table and looks at the values over time, interpolating between the 1 second breakpoints and applies this to the playback speed of the audio while simultaneously recording the output to disk. 

The net result is a lookup table and a bit of ramping between values; far more computationally efficient than the junk equation above! Sonically if produces a seamless transition from inaudible, through rumbling sub-bass, murmuring rumbles up to urgent build and finally a howling drive-by.

Turbo is due for release in October on Spotify, iTunes, Bandcamp etc. (click the links to go direct to the artist page). For more info see www.virtual440.

Susurration

Sound-Sculpture commission for Golygfa Gwydyr

Susurrate (Latin): a murmur or whisper of leaves, wind etc.

The piece works with the shapes of the woodland to create a reflective space. Resonant metal bars are suspended from various trees and branches sonically and visually amplifying the apparent characteristics of each.

With the notes being suspended from the trees, the branches dictate something of the visual shape. Thus the impression of a majestic or skeletal specimen becomes heightened.

This is exaggerated by the notes used. In the case of a gnarled tree, if the notes used create something bright, a high pitched and major sound; it all of a sudden feels like a cheerful plucky little tree. Whereas if darker diminished tones were chosen the atmosphere and presence feel more menacing.

By itself the sculpture is largely silent, requiring a strong gust or outside intervention to create a sound. Instead, it remains quiet, highlighting the shapes of the canopy in an alien, almost ritualistic way.

On exploring the space members of the public can find beaters secured in place with which to tap the bars and bring the space to life. If audience members want to hear more than one tree at once in the space then they will have to cooperate and play as an ensemble due to the distances involved.

Each tree has a specific chord cluster, the sounds and appearance of which reflect the artists’ response to working with that particular organism. Some are sunlit and beautiful, others are brooding or foreboding, and everywhere in between.

The work is as much about music as the potential for sound. It is about heightening awareness of the environment, the magnification of space and listening and the pockets of existence between, before and after notes.

The work will be on display in Golygfa Gwydyr Llanrwst from 7th August throughout the Eisteddfod week and for longer if nature permits.

Turbo

Turbo is a piece of music which I have been working on for a while. It draws on three separate sound sources namely two Formula One cars which raced when I was young, the Lotus 97T and the Ferrari 412 T2, as well as a Scalextric set. These three sources form the basis of the track with the remaining sounds derived from them or synthesised from first principals.

The engines of that era sounded very different. It was a less regulated time, before the advent of widespread electronics, the introduction of hybrid engines or the level of concern about petrochemicals and their environmental impact. While there have been many changes for the better over the last thirty years in F1, the sound of the grid is not one of them.

While working with the audio to create something musical rather than a historical document several things jumped out at me. Firstly it is amazing how melodic these vehicles are. From the chord of D and A created by snapshot sample of a car in the distance to the almost choir-like textures created by zooming right in on only a very narrow set of frequencies it really should not have been a surprise how ‘tuned’ race cars are. Secondly, the sounds are highly cyclical, but in an evolving way which can be exploited to find not only glitchy textures but also built on and augmented.

As well as drawing on the sounds of the turbo engine the idea of a turbo spiral extends into the structure of the work. There are four main sections to the music which repeat and develop with increasing rapidity. If you travelled around a spiral at a constant speed you would find a new section of music every ninety degrees. As the spiral tightens the sections become shorter, leading to a whirling inexorability in the final stages.

This idea of structural acceleration extends to a Ferrari engine sound heard throughout the work. It starts very low and slow; five-thousandths of its original speed and then gradually ramping up to become audible, first as a bassy rumble before transforming into glitchy background antics before flying past at full speed at the end.

Creating this piece has been an interesting challenge; trying to balance something which is intellectually rigorous (e.g. the golden-spiral mapping and computing), along with creating something which is engaging to listen to. I have tried to convey something of the excitement and nostalgia the source sounds bring to me, but also that tranquil space that you find in split seconds of extreme focus, the loudness and brutality of the spectacle, and hopefully something beautiful.

Turbo is dedicated to my Dad who was always a massive fan of motorsport, particularly Formula One and occasionally Scalextric.

Available online on iTunes, Spotify etc. from 15th October 2019.

 

 

 

New music in the pipeline…

Artefacts.
Recently I was given a mixtape on cassette, the first ‘new’ cassette to come into my possession in well over a decade. The sentiment was amazing and it’s a wonderful thing but listening to it the sound quality was less than great being a generational copy compiled from several other tapes and recordings from the radio. Oddly the fluctuations in pitch, EQ colouration and stop start edits did not seem to matter as in the intervening years they had taken on a charm; linked to a time, objects and set of actions which have been technologically superseded which now makes this a creative choice.

The wow and flutter on the tape have become like the adze marks on the beams of rustic cottages, once rough but now a mark of the time, the technology and the interaction between human intent and facilitation.

Artefacts is a piece of music made by pushing digital and analogue audio equipment into extremes of its range while feeding a “silent” or null signal. After repeating this process a number of times the quirks of the system gradually come into focus with the glitches and biases of the equipment becoming amplified by repetition, sometimes with surprising results. These experiments were recorded and then used as material to create this piece.

Space To Think

In about September I was commissioned by Bangor Music Festival to compose a piece of electroacoustic music for their February 2018 event, along with a series of education workshops. I really wanted to do this and it was looking like it was going to be an amazing autumn and early spring of creating cool stuff and having fun; then the floor almost literally gave way.

Following a period of ill health my Dad took his own life in mid October and unsurprisingly this hit me really hard. It is not so much the sadness which is debilitating but the feelings of numbness, rage and lethargy that suck the capacity for creativity away. In my case my Dad and I got on really well, he was a role model and someone who had a massive influence on me throughout my life, when something so seemingly at odds with everything you have ever known happens all the basic assumptions that you make in life come into question. I would even look at my feet when walking down stairs, not through shock or physical instability but because I no longer trusted the assumption that I knew where my feet and where the steps where. It was certainly no mindset to take creative decisions in, they are so vague, so intangible and impossible to verify that the simplest starting impetus threw up paralyzing indecision.

It was at this point that I sadly informed Guto the festival director that I couldn’t fulfill the commission. I have never had to do this before and it left me feeling awful, but also slightly relieved.  There followed a period of calm, I got back to doing some work and I managed to get off the antidepressants (citalopram) which had been prescribed to help me sleep, level me out and stop catching things out of the corner of my eye. In late December I got a phone call from Guto offering to take some of the festival work back, but once again asking if I would like to compose ‘something’ for the finishing concert.

I find it really hard to sit down and just make noises or compose, some people start from an initial sound or a feeling, I tend to find some sort of idea or framework to hang something on and then can go from there. I though about this for about 24 hours, it was an incredibly kind offer which Guto had made, and my head was clearing. I went for a run in the hills, it happened to be early as I wanted to make the summit of a mountain near to us to catch the winter solstice sunrise and on the way up the ideas just struck me.

The theme of the event this year is space and I am happy to say that the work shared a stage with Birmingham Ensemble for Electroacoustic Research (BEER). BEER had worked in collaboration with the Art@CMS project at CERN in Switzerland, using real-time sonification of data streams from the Large Hadron Collider, the world’s largest and most complex particle accelerator. This is something which it is foolish to compete against; that, and the fact that I literally have Scott Wilson (of BEER)’s book on coding in Supercollider sat on my desk. Thus I chose to take a different tack and rather than approach it from an analytical and scientific angle I went for something closer to home.

Space To Think – Ed Wright 2018 (8 channel surround sound audio)

A lot of what is in the popular imagination about space and space travel is precisely that, imagination. From the Barron’s Forbidden Planet through to the electronic squelch of radio communication a lot of what we think of as space related is a very human construct. What fascinates me is how much of what we believe sounds as if it comes from outer space or under the sea (or for that matter any environment out of our direct experience) is actually a result of dubbing and sound design in the media. As a culture we have bought into the idea of rockets rumbling as they go past, even though there may be almost nothing in the void of space to transmit the sound and the glockenspiel twinkle of stars is almost as real as the piano wire scrape of the Tardis. This provides a fantastic palate of subverted fantasy with which to create and explore a rich and varied sound world. Apart from the use of two pieces of NASA archive; launch and countdown, the rest of the sounds used I have recorded and shaped myself.

Great delight was taken in recreating a few iconic ‘other worldly’ sound objects and effects along the way, 50 pence pieces were rubbed down piano strings to provide the basis for a tardis noise before looping and adding spring reverb. Humming strip lights were close mic-ed to create light-sabres, and some generative coding brought about drone progressions similar to the opening of Star Trek. These and many other sounds were used as the raw materials of the piece and then developed as the different timbre interact and evolve. The result is an acousmatic work utilizing a wide variety of sounds from analogue synthesis through to simple dislocation and out to generative algorithms creating an apparently extra-terrestrial environment in which our earthbound ears and minds can roam.

Many thanks to Guto Puw and the Bangor Music Festival for their kindness, understanding and faith.

In memory of Brian Wright

Ricercar (for electric violin and stochastic step-sequencer) 2016

Ricercar was created as a way to create evolving polyphonic textures in a ‘solo’ violin piece. It uses a midi foot controller (currently a Behringer FCB1010) to control an electric violin into a piece of software created specifically for this piece.

Testing at home before the first performance
foot controller, violin and laptop visible in the
chaos of pre-event preparations

The work is essentially fugal, relying on live sampling to create the layers around the instrumental part and uses a 3 layered sequencer to achieve this. Each layer contains a series of buffers which can be recorded into. The top layer has seven 5 second samples, the middle has 5×17 and the lower has 3×71 second samples. These all prime durations so when left to their own devices they will take a long time to ever repeat in precisely the same configuration. Using a foot controller to trigger when to start recording and which buffer to record to or overwrite, thus it is possible to gradually build up a four part texture using the three sampler ‘lines’ and the live violin.

Overlapping prime blocks 5,17 and 71

In itself this is passable, but could be rather recursive and very quickly get repetitive unless loops are overwritten regularly, which in itself could become an oft-repeated task. This has been overcome in 2 ways. The first is that each time a sample is due to be played there is a 50% chance that it will not be in which case the sequencer just moves on and waits until the next step is ready and then re-rolls its virtual dice. When scaled up over each of the 3 layers of fast, medium and slow samples this means that there will probably always be something playing (depending on how many samples have had audio recorded into them!) but the thickness of the texture will vary.  The second way that diversity is added is by changing the playback speed of each sample. As a sample is triggered the sequencer takes a decision as to what pitch/speed to play the audio. This varies over four octaves (two up and two down) and results in a shift in playback of between quarter speed and four times as fast. The speed changes are in discrete even tempered steps and thus a broader sense of harmony and polyphonic/contrapuntal line can be achieved.

In addition to this audio focused processing there are 2 global controls. The first is how fast the sequencer triggers each step. This in itself does not affect the length of individual samples so at extreme speeds loops will overlap in a densely fired texture or conversely there may be a lot of space and silence at very slow speeds. The last of the controls is volume of playback, which when used carefully can not only help to balance the live and processed material but can greatly increase the sensation of articulation and dialogue.

Within this framework the performer is free to improvise, guided by the constraints and freedoms of the instrument, themselves the hardware and software.

Enjoy

Video extract taken by Diane Evans at OscilloScope 28/6/15

Max MSP Basics

Here is some stuff I put together a while back. It may be useful for some people 🙂
Ed

ground loop

Contents (click to jump to section):

What is Max/MSP?
Working with audio
Numbers, messages and lists
Programme flow and control
Making patches simpler
Playing audio samples
Simple MIDI control
Enveloping and cross-fading
Designing the user interface
Soundfile playback and timing.
Refining soundfile playback control and timing.
More elegant approaches to additive synthesis.
A better way to create polyphony: poly~
Breaking out; physical I/O and Arduino.
Working with acoustic instruments
Audio processing
Further audio manipulation
Jitter
Jitter II
Gen~
OSC
Javascript in Max
Algorithmic composition

What is Max/MSP?

Max/MSP (often just called ‘Max’) is a ‘multimedia programming environment’ which will allow you to create pretty much any kind of music or audio software you can think of. It can also handle video using a built-in extension called ‘Jitter’.

To get more of an idea of what Max can do, visit the website www.cycling74.com and click on the ‘projects made with Max’

View original post 24,603 more words

If you need the loo, please go before listening to this piece!

Anatomy of a Mountain Stream: quadraphonic fixed media, binaural version.

Field recording & processing programming: Edward Wright

We often take things for granted until we look carefully at them. During the cold snap of the winter of 2011 when the snow had dampened all the sounds I bravely/foolishly balanced a surround sound recorder on a rock in the middle of the stream that runs down from the Carneddau, through Parc Plas Mawr in Penmaenan on its way to the sea.

Through manipulating the playback speed of the resulting sound-file it was possible to expose many details of the sound that are often obscured by our ‘normal’ way of listening. By simply changing the sampling rate, we can enter what feel like different sonic dimensions where the very large, and minutely small sonic structures become far more apparent.

Effectively this means that I have slowed down and sped up the audio. More precisely a computer or CD player reads through audio in a number of steps much like you would go through pages in a flick book but a lot faster (CD reads at 44100 ‘steps’ per second).

All that I have changed is how quickly those steps are taken. What this does is to not only change the pitch of the audio as the sound waves become compressed or stretched out, but also to chance the perception of events. Things that seem a blur become a series of discrete happenings and events that seemed slow and random start to show striking regularity when viewed over a longer (or more compressed) time frame.

In this piece the original 8 minute sound-file is played in its entirety, but the speed has been mapped and composed to create the framework of the piece. The audio was recorded on a Zoom H2 at 4chan x 48kHz x 24 bit, processed in Max/MSP 5.

This version of the work had been mixed to give an approximation of the quadraphonic set-up of the speakers (i.e. 2 in-front and 2 behind) on headphones.

This has been achieved by playing a sound impulse from each speaker and measuring how it gets to a listeners ears. A sound from the extreme left will take slightly longer to reach the right ear than it takes to get to the closer left ear. Also the journey that the sound waves have to take around the head will absorb some of the energy, although not evenly across all pitches, changing fractionally changing the tone of the sound by the time it reaches the further ear.

 

Image from http://www.cns.nyu.edu/~david/courses/perception/lecturenotes/localization

If you played a sound from the right front speaker (for instance) and recorded that sound from microphones placed in the ears of a listener you can compare the signal from the speaker with those that have arrived at the ears. From this point we can work out what the change is and can also apply that change to any other sound.

This has been scaled up to the 4 separate audio channels and processed (impulse convolved) with the spatial data collected from the in ear microphones hence why you need to listen on headphones to get the full effect

SO, PLEASE ONLY LISTEN ON HEADPHONES NOT ON LOUDSPEAKERS!

Tuning a violin….

This is from a piece I have written for internetviolin.com hopefully it will be of use to some people as I know it is a cause of much difficulty and frustration. Also any feedback from those more experienced violinists out there would be great!

* * *

Tuning

Tuning your violin is one of the most important things to get right as if the instrument is not in tune it makes getting a good sound a lot harder than it already is. So here are a few hints and ideas for those of you starting out.

STAY SAFE! Don’t over tighten your strings as this can cause them to snap. Keep your face, and especially eyes, out of the range of a potentially snapping string.

Look after your violin! Only try to tune one string at a time and always maintain some tension on at least one string. The bridge of your violin, and to a lesser extent the sound post (inside the violin roughly under the E side foot of the bridge) are largely held in place by the pressure of the strings. If you slacken everything off they can fall down!

Tuning a stringed instrument relies on some basic physics, in that the tighter a string is pulled the higher pitch it will give you, think of it like a very espensive rubber band.

Two possible ways to tune

First there are the main tuning pegs, which are very useful especially if your instrument is a long way out of tune.

Secondly your violin may have one or more fine adjusters attached, or built into, the tail-piece. These are arguably easier to use in that the control is a lot more precise and have the additional bonus of being less likely to cause string breakages because they can only tension so far before you run out of thread.

From this point the rest is simple in theory; if the string is too low in pitch (flat) you tighten it, if it is too high (sharp) you loosen it. However, putting this into practise can sometimes require a few practical skills.

Reference Pitches

In order to get your violin in tune it helps to know what you are aiming at. The four strings of the violin are G D A & E.

Here are the four notes that the violin is tuned to. G is the lowest sounding note and usually has the thickest string; with the violin placed on your shoulder it is the string furthest to the left. The strings are then arranged G D A E from left to right.

You can check these against anything that you know to be in tune, such as a piano, tuning fork or for that matter an electronic tuner.

Click the letter to hear each pitch and check that the sound coming out of your violin matches that of the clip. I have included two different types of sounds, one being a piano, given that is what is often tuned to in the ‘real world’ and the other being a sine tone which is theoretically the purest pitch reference.

Sine Tones:

G D A E

Piano:

G D A E

Click the letter to hear the audio.

Assuming that your violin gives notes that sound like those above then your don’t really need to read on right now, get on and play!

Tuning with adjusters

Assuming that your violin is only slightly out it is probably easiest to tune it with the fine adjusters at the tail-piece. Pluck or bow the string to determine if the string needs to be made higher or lower and tighten or loosen the screw head of adjuster connected to that string. It is probably better to only move it by small increments between re-checking the note to prevent over tightening. When you are happy with the note proceed to the next string.

Tuning with the pegs

Often tuning with the pegs will be the only option as before it is imperative to only move it by small increments between re-checking the note to prevent over tightening and snapping the string. It is best to check the pitch by plucking, or bowing the string whilst turning the peg to the right position. Pegs are a very old method of controlling the tension on a string and rely on friction and the fact that they are tapered to make them work, so the trick to making them stick is to twist and push, like you would when using a screwdriver or cork screw.

Bowing vs. Plucking

In order to see if your violin is in tune you need to hear it, often as you are tuning it. There are two ways to do this; plucking the string or bowing it. Plucking is far easier in that you can rest the instrument on your knee or on your lap and turn the peg/adjuster with one hand whilst plucking with the other. Bowing requires that you hold the violin under your chin and turn the peg/adjuster whilst bowing with your remaining free hand! This is not for the inexperienced or faint hearted and should be tried out either with assistance or over a very soft landing as if it slips from under your chin it is almost impossible to catch by yourself.

The reason why so many people bother with learning how to bow and tune at once it that it is far more reliable. Not only can a bowed sound give a more sustained volume, but it the plucked tone is harmonically less stable and tends to get noticeably lower in pitch as the sound decays.

However until you need the level of performance that bowing whilst tuning provides it is probably not worth the risk of dropping your violin!

Problem Solving/Other Considerations

Once you have got your strings in tune it is best to check each in turn. As the strings are all tensioned on the same instruments the pull acts over the entire instrument, so big changes to one string, can result in smaller changes to others.

If a peg does not stick it could be for three key reasons:

1. The string is pulling the peg out. This is by far the most common! Look at where the string meets the end of the nut. If the string meets the peg significantly further towards the narrow end of the taper of the peg, it will effectively be pulling the peg out of the peg box. To remedy this simply slacken the string off by a couple of turns and then tension back up, whilst winding on a fatter part of the taper closer to the wood of the peg box.
2. You may not be pushing the peg far enough in, please be delicate, but it does need enough force for friction to do its thing.
3. The peg does not fit the peg box properly, in which case ask a reputable specialist to look at it.

If your run out of thread on your adjuster simply loosen the main peg, twist the adjuster back so that the screw thread is to about 50% depth, then take up the main slack on the tuning peg. You may have to fine tune with the adjuster a little to complete the process.

Make sure the bridge stays vertical. Its feet should be approximately between the cross bars of the f-holes, and the top of it should be in line too. Repeated tuning and especially changing of strings tends to drag the top of the bridge up the instrument. This can be detrimental to the sound and playing and in extreme cases can lead to the bridge falling over. If your bridge does start to lean, then simply slide it back into place, loosening the strings slightly if required.