Transcript Compositional Technology

COMPOSITIONAL TECHNOLOGY
WEEK 4
APPROACHES TO SONIC MATERIAL
PITCH
A sonogram from sounds recorded in water near
the North Pole. The trace opens with quiet
background noise with a slowly descending
unfocused high sound. There is a noisy percussive
sound at around 0:15, and the high pitch continues
to drop. This high phenomenon repeats and is
joined by strongly harmonic ‘pitched’ note which
continues through the rest of the trace slowly falling
in frequency.
http://www.awi.de/fileadmin/user_upload/News/
Feature_Stories/PALAOA/icesounds/mystic_sounds/
sonogram.jpg
•
The use of pitch is of fundamental importance to most types of music.
Electroacoustic music is no exception. There are some important differences to
the way that we understand and use pitch, largely due to the unique set of
tools available in the studio.
• Most western music is dominated by the idea of notes and rhythms. Pitch and
duration are easily quantifiable either in conversation or notation by the
regular division and codification of these parameters. With Electroacoustic
music we are free to experiment with a more holistic continuous understanding.
At a given time a sound can be quantified and defined by its
pitch, volume, and timbre. This is taking a snapshot, so
disregards issues such as duration, relative loudness and
harmonicity. Pitch, volume and timbre can be thought of as a
3 dimensional space in which a sound could be plotted. In the
case of clearly defined ‘notated’ music there are a number of
set possibilities e.g. the chromatic scale, pp-ff and orchestral
instruments. Looking at the Rubik’s Cube analogy these sounds
would be occupying the black lines of the potential space.
With electronic control and the loss of the need to define the
space to the performer we are free to use the entire pitch
volume timbre space as a continuum. Thus Acousmatic music
rarely uses ‘notes’ and ‘harmony’ in the traditional sense, as it
is one of the few musical forms that does not necessarily have
to!
•
Our understanding of pitch is quite complex. Fundamentally our notion of the
pitch of an object is based on the frequency at which it is vibrating. If we were to
hear an object vibrating at 440Hz it would be what describe as an A, as that
pitch doubles (to 880Hz) we go up an octave and if it were to half (to 220Hz)
we descend by an octave.
•
This is very simple in the case of clear sounds such as a sine wave, however some
are more complex. The Sonogram trace on the first page shows a number of
sounds running simultaneously. The most striking is the long harmonic sound with
the ‘radiator’ pattern of regular harmonics. In this case the note that we would
hear as the ‘pitch’ is the lowest and loudest harmonic (the 1st, or fundamental
harmonic). However in the case of bells and other less harmonically ordered
sounds there is no definite centred pitch but rather a series of harmonics that
come to the fore at different points over time.
•
Timbre or spectrum can be thought of in the following way, this then feeds into
our idea of pitch.
• Timbre or spectrum can be thought of in the following way, this then feeds into our idea of pitch.
Pitched
•
Stable
Unstable
•
Noisy
• In addition to this pitch can then be broken down with the following space:
Static
Continuous
Quantised
Dynamic
•
•
Common methods of the use of pitch
Correspondence
This is achieved when a number of sounds share a large amount of the same pitch based material.
One sound can feel connected to another if it is heard in quick succession at the same pitch. This can
even be true with strongly related pitches such as at half the frequency. Correspondence, or lack of
it, can often be the reason why sounds do or don’t feel like they ‘go together’. Quite often to achieve
this you will need to pitch or time-shift some material to obtain pitch similarities.
•
Colouration
This is where largely un-pitched (or noise-based) sounds are processed in order to bring out specific
frequencies. This can be done with tools such as: EQ, de-noising, or even extreme gating. This can
result in a large variety of effects and forms some of the basis of subtractive synthesis.
•
Aggregates
A pitch aggregate is simply a collection of pitches at the same time, rather like a less specific version
of the term ‘chord’. Where the excitement comes is the very large grey area between an aggregate
made from a number of sources (effectively a noisy chord) and a solo in-harmonic structure. Complex
evolving tones and gestures can be easily built up this way, with the potential for transformation of
sound and meaning thrown in.
• Definition
The use of pitch can bring clarity to ideas, by centring them at different points in the continuum.
• Gesture
Pitch can be a powerful tool for creating gesture. Glissando is massively useful, as is the use of
disjointed pitch transformations. These gestural events can be applied to individual objects, or
indeed entire passages of music.
• Structure
At a larger scale, pitch can be very useful for defining structure. A section may consist largely of
low sounds or in the case of two different subjects one may consist only of midrange sounds
whilst the other may be constructed solely of high and low material.
• Systems
There is nothing wrong with using sounds and structures that refer to established pitch systems
such as modality or the tempered scale. Within the language of electrnic music it is often a very
powerful statement to opt for the simplicity of such systems. However do not over-do it, keep
things evolving and interesting.
SPACE
•
•
Space and historical precedent
We exist in a spatial environment and our understanding of it is important to our day to day
survival. Space is an innate part of our understanding of most music, even if we are not always
aware of it. Listening to a symphony orchestra or any ensemble is an innately spatial experience;
the composition is diffused based on a complex set of rules. These are governed by a pool of
possible pitch, duration volume and timbre choices. More simply the music is placed throughout the
ensemble based on the instruments performing it (consider the motion of left to right and treble to
bass in a conventionally arranged string section). Historically there are examples of music such as
Gabrielli’s use of separated choirs that make use of space as an overt parameter, but it is since
the rise of electronic music that this has become more widespread.
• Recording
Before even opening any audio editing software we can make choices about
the stereo information contained in our recordings. Microphones can be
positioned to capture a wider or narrower stereo spread and sound can be
captured stationary or from an object in motion.
•
Towards a classification of stereo space
Stereo is created by the use of 2 discrete audio channels however we can create far more than this simple 2
channel set-up would suggest.
•
We have 3 possible planes of spatialization for a given sound:
Horizontal plane (simple left/right balance based largely on amplitude)
Virtual plane (depth, created by psycho-acoustic effects employing processes such as reverb and EQ)
Implied plane (height, largely created by frequency and the construct of ‘low and high’ sounds)
•
In addition to this we have 2 basic states of a sound object within that space:
Static
Dynamic (movement of a sound in one or more plane)
•
At a higher level of classification we have concepts such as the predictable motion of a sound within space,
moving in a spiral for instance. It is also possible to then consider the interaction of sound objects with each
other in the stereo space, as well as the linking of spatial motion to implied musical gesture, however we
will focus on the lower level concepts initially.
•
No matter how complex they are to describe, every sound has pitch timbre and volume characteristics. They
also have a place within the stereo field whether you have specifically defined one or not. After all if you
can hear it, it must come from somewhere!
Horizontal placement
• Horizontal placement can be measured physically by comparing the loudness of one channel
to the other, in this sense it is a ‘real’ parameter.
• Do not pan anything absolutely left or absolutely right. This will result in the stereo image of
the recorded sound being flattened to mono and the sound having no presence in the
opposite speaker.
• Try to use the full available width of the stereo field.
• Ensure that your mix does not become lop-sided. It should balance in the middle not favouring
either the left/right extremes and not having holes in it by favouring either the centre or the
edges.
• Movement is very easy in the horizontal plane. Simply pan it.
• Different positions in the left/right plane are useful for defining different sounds and ideas.
However it is worth remembering that our perception space is not as accurate as you would
be lead to believe by programs such as Pro Tools.
Virtual placement
• An impression of depth can be created by:
NEAR
Loud
Less reverb
No EQ More
FAR
Quiet
More reverb
EQ (incl. less HF)
Don’t place sounds too far back or with too much reverb for too long as it will
tend to be lost. Also, most performance spaces have their own reverb so you
don’t need to add in too much.
Implied placement
•
The concept of ‘high and low’ sounds as analogous to frequency is almost culturally
universal. As well as this bass sounds can be more easily physically experienced
transmitted through the floor conversely high frequency sounds less so.
•
Frequency differences can help to define different ideas.
•
Many low frequency sounds contain high frequency harmonics so a low pitched sound
does not necessarily mean that it is exclusively placed low in the implied space.
•
To create specifically low sounds it may be necessary to use a filter to remove higher
partials.
•
Just as with the virtual and horizontal planes motion though such as glissando can be
very effective, providing it is not over used.
Combinations
• Obviously this is simply a breakdown of the available parameters.
Combinations of movement can be used to great effect and form a part of
what defines the overall genre of acousmatic music. They can also be good
fun.
TEXTURE
• Texture is a fundamental part of the way we
understand music. In conventional music, texture
is often thought of as a function of a number of
factors, mainly; harmony/polyphony, rhythm
and orchestration. In a sense this holds true for
acousmatic music, in that texture is the
comprehension of changes in the music over
time. These changes can be in pitch, volume or
timbre and can be relative to other parts of
the piece or relative to our expectations of a
work.
Cordierite hornfels at, Caldew River, Carrock
Fell, Lake District, England. Keele collection.
http://hypocentre.posterous.com
• Texture is not really a continuous parameter such as pitch, although the objects
it describes can be seen as such. In everyday usage ‘texture’ or ‘textured’
usually refers to sound objects or structures with a lot of changing internal
information or perceptible internal detail. These are what we would commonly
call ‘course’ or ‘rough’ textures. Obviously the term texture can also refer to
smooth textures, although this link is not as strong, in that when we describe
something as textured we tend to think of something ‘at least slightly bumpy’.
Rough
Textured
Smooth
(no discernable texture?)
Creating and controlling texture
•
Like a lot of other musical parameters texture can be both static and dynamic in that
it can either evolve or not. This can be thought of at two different levels those of the
quantum (individual elements of texture) and global level. Where texture becomes
special is that it is a sophisticated combination of a variety of factors such as pitch,
volume and spatial information
Quantum characteristics
Global characteristics
Pitch
Volume
Length
Panning
Timbre
Panning
Density
Focus
Pitch
Volume
Timbre
Panning
Trajectory (evolution of the above)
Quantum level control
• There are two main methods of creating texture additive and divisive:
Additive texture.
• This is where different sounds are brought together to form a larger cohesive
entity. This can be achieved by a variety of different methods
• Mixing – Quite simply adding lots of sounds into the mix and balancing them
as required if this is done on a large enough scale the tendency is to stop
perceiving individual sounds and focus on the overall cloud
• Sampler sequences – Loading sound objects into a sampling system that can
then trigger them. This is useful in that gestures can be repeated and modified
relatively easily. In addition to this most samplers offer control over pitch and
The tendency at first is to
speed of playback which can add further detail.
notice the overall flock and
• Granular Synthesis – In granular synthesis sound is dived into small grains
typically between 1-100ms, although longer may be required for specifically
textural effects. These can be mixed with grains from other sound sources to
create new sounds and textures.
its shape, not individual birds.
http://en.wikipedia.org/wiki
/Flock_%28birds%29
Divisive Texture.
• These methods start with smoother sounds and break them
up in some way.
• Cut and splice - editing to create discontinuities. This is
highly effective but can be very labour intensive if working
with large amounts of material.
• Convolution- Using 2 (or more) sounds to interact, thus
creating the potential for twice as much detail at one time.
• Gating - Use of gating to only have the louder portions of
a sound
• Shuffling – A technique that is very useful with purpose
built GRM plug-ins.
•
Global level control
•
In many cases textures can be thought of as a single element or sound. As such they
can be used and handled as a single sound object, as well as being regarded as a
composite of many different elements. Many automated processes such as shuffling,
granular synthesis or sample based procedures can offer levels of control over the
global output such as density, pitch or focus.
•
Textures can be built up and dismantled relatively easily from their constituent parts.
Specific ‘bounced’ textures can also be layered and mixed together. In addition to
this all of the processing that is available with a single sound object (such as filtering,
pitch shift, gating etc.) is available for a single bounced texture, thus it is possible to
shape the overall result.
• Using textures
•
• The ease with which textures can be created often leads to their overuse. They should be approached with
caution as the volume of detail can become fatiguing very quickly and lead to passive listening and
boredom. They are also sometimes hard to justify musically in that starting and stopping a texture is often a
lot more problematic than keeping it going or not starting at all.
•
•
•
•
•
•
•
•
•
Potential uses:
Variation and development of objects and structures
Interaction of objects and structures
Rhythmic interest
Background detail
Screening (partial masking or obscuring)
Masking
ARTICULATION
• In music articulation refers to the way sounds are distinguished from, or
connected to each other. Articulation can refer to the way that individual notes
are played such as staccato or how sections are joined together to create
musical flow. Articulation comes from the Latin articulare meaning ‘to joint’ and
in music refers to the way that ideas interrelate in time.
Articulation
Seamless
Disjointed
Causality: Joining sounds in time.
One of the most puzzling and frustrating parts of acousmatic composition can
be making the transition from one sound or event to the next. Quite simply, how
to join them?
The problem is often one of cause and effect. Within the computer may
physical laws are put on hold, we can easily have the sound of a paper
burning underwater for instance. Unfortunately many times our brains will not
entirely let us forget simple real world issues.
Consider the cartoon frame. To break down what we are actually perceiving
here could take an awfully long time, but suffice it to say that with a mixture of
culture, common sense and several million years of evolving we see that there
is a (not very realistic) representation of a coyote and a bird. The bird
appears to be gloating and the Coyote appears to be in want of terra firma.
From the visual and cultural context we instantly know he is falling we might
even guess the sound he may be making, it would be hard to imagine much
else without outside intervention e.g. a very large eagle.
In electroacoustic music it is quite possible to make one sound follow on from
another for no obvious reason and that is fine providing that is acceptable.
Sometimes it simply stops the music from making sense, so here are a few ways
to get around this.
• Recording
• In order to make your sounds feel more ‘real’ consider how you are capturing
them. It is quite possible to record sound objects by taking samples from the
real world. It can be very useful to take extended phrases, a performance on
the sound object in a real world sense, as this can provide a very tangible
reality when played back.
•
•
Anacrusis
•
Dynamic. A rapidly rising crescendo can be a compelling lead into an event. This often works
better if issues of ‘loudness’ (contextual volume and timbre etc.) are addressed rather than
simply turning the volume up.
•
•
Pitch: Swift glissandi can imply motion towards or away from something.
•
Repetition: A simple way to create expectation is to have done something before
The term anacrusis is taken from conventional music and refers to an up-beat preparation to a
down-beat. In electroacoustic music it refers to anything that sets up the expectation of a
following event, this can function on a number of levels and is not strictly a rhythmic element as
the name would suggest the chord progression IIb7 V7... has the same effect in western
harmony. Some simple methods of creating anacruses are:
Referential: In the case of real world objects often one sound may be expected to follow
another e.g. a squeaky door closing could be followed by the bang of it shutting.
• 3 Card Trick
• The three card trick builds upon the idea of repetition. Our brains like to find
and predict patterns. When we hear an event and then hear it repeated we
tend to assume it may happen again. When this does happen this expectation
is fulfilled and there is a sense of ‘round off’ to the pattern. New material
introduced with the third repetition also often fits.
Overlapping
•
Overlapping is as simple as the name would suggest. Sometimes all that is required is to fade a new
piece of material in. There are subtle variations on this technique such as running the new material
at a very low volume level under the old before bringing the old material to a conclusion. This leads
to a sense that the new material was always there even if the listener did not know it.
Punching and Distraction
•
Punching and distraction are two less subtle ways of articulating material, but they basically rely on
a similar set of phenomena.
•
Punching: Quite simply putting a loud and noisy event over a difficult join between two or more
elements. This can be very effective for marking changes in material or section and potentially very
useful for rhythm if the punch object is part of a wider rhythmic framework.
•
Distraction: This is what is says. The listeners’ attention can be drawn away from difficult technical
elements by simply doing something else ‘flashy’ at the same time, in much the same way as a magic
trick.
MONTAGE
• Montage, Mixage, Filtrage
• In the early days of musique concrete, there were two main techniques, those of; mixage (mixing or layering
of sounds) and montage (putting sounds together in sequences). Intrisically adding sounds ontop of, or beside,
each other. Only later did the idea of filtrage (changing sounds) really take off. This was partly due to the
technical difficulties of transforming sounds in those early days, and today it is one of the main methods used
in acousmatic composition. Today mixing and processing are comparitively easy with programs such as Pro
Tools. Montage tends to be neglected as it is less glamourous than using new pieces of software and often
involves more work than mixage and filtrage. Montage may refer to the simple act of arranging or composing
sounds along a timeline, it may also refer to the interactions of these sounds, a particularly noticable fast
cutting of objects often being refered to as ‘a montage’, when in truth it exists all thr way through the work in
one form or another. In its strictest form montage is a purely horizontal phenomenom as sounds are executed
one after the other as opposed to mixage where sounds are layered ‘on top of’ each other.
• There are a number of ways that montage can be used:
(Un)reality
• Montage can be a powerful tool for creating environments and virtual spaces. These can be
realistic such as a recording of a room full of people talking followed by the opening and
closing of a door into the sound of a spring day. Equally we create impossible justapositions
such as opening the door in the previous example into the sound of the internal workings of a
pocket watch.
Poetry and metaphor
• Part of the real excitement of acousmatic and electroacoustic composition is the use of real
world sounds and making use of some of the connotations they may have. With the placement
of sounds in time it is possible to create a wealth of complex meanings based not only on their
actual sounds but also based on what they symbolise for the listener.
Developing rhymic material
•
Most music requires at least some rhythmic material. This does not necessarily mean
beat-locked repetitive material. A repetitive beat is simply one (very specific) kind
of rhythm there are many others that we may be trying to bring out. For example a
crackling fire is rhythmically very beautiful, but is not at all repetitive.
•
Through montage we have control over rhythm in two ways. The first is in our choice
of sound. Every sound has its own internal rhythm, based on factors such as its
texture, pitch and amplitude envelope, the specific sounds we trigger will have an
effect on the rhythm and pacing of the music. The second element of control builds on
this, in that we then have control over when these sounds are triggered. An effective
rhythmic montage will often use the ‘natural’ rhythm of the sounds and assemble them
into a larger rhythmic sturcture.
• Heirachical
• It is easy to think of processing or mixing as something you apply to a sound object and
placement in time as rather arbitrary and the first thing to do in order to get onto the
interesting work. If we redress the balance of montage, mixage, and filtrage and view them as
3 equal disciplines or indeed as being in descending order of importance we gain a different
perspective on composition. This gives rise to ideas such as; processing different versions of a
sound and then creating a timeline or montage as if they were original sounds, or using
mixage to create new objects which are then bounced and arranged into a composed track.
• Creation of new timbre/synthesis
• Montage can also be used to create new timbre. Carefully splicing the attack portion of one
sound to the resonant portion of another can give rise to strikingly ‘new’ sounds. This relies
upon the fact that most of the information we use to characterise a sound in terms of what it is
is contained in the first few milliseconds. By working carefully we can create some very
unusual objects.
Context
•
Montage is essentially the judgement of the timing of sounds. Therefore we can use it to create
different contexts around a given object. A sound may be very quiet and muddy in the context of
a large amount of loud bright material, but may in turn appear very loud and bright in the middle
of very delicate sounds. The key is variety and judgement.
Practicalities
•
•
Montage is very powerful. It does take time and effort so here are a few tricks to speed things up!
•
Take a long stretch of material and cut another smaller piece into the middle of it, repeat with
another smaller piece in a different place and so on into smaller and smaller units, then listen and
audition it.
•
Go random. Take a few layers of material that have lots of slience in and play them at the same
time, then adjust as required and pick out the good bits (if any).
Firstly practice editing, a really powerful montage can be the result of hours of editing a couple of
seconds saved per edit will add up.
PICK A SUBMISSION FORMAT, OR DEVISE YOUR OWN
AND GET IT CHECKED OUT THEN GET ON WITH IT 
1.
Submission of a portfolio of 3 stereo tracks totalling approximately 8 mins,
comprising music made from entirely found sounds and processed sound objects.
2.
Submission of a portfolio of 3 stereo tracks totalling approximately 8 mins,
comprising music made from synthesised sounds.
3.
A 3 minute demonstration of your own digital instrument built in Max controlled using
live triggering of your own sampled and processed audio.
4.
A 4 minute demonstration of your own digital instrument built in Max controlled over
by iPhone touch screen over OSC.
5.
6.
Generation of an 8 minute notated score by algorithmic methods
A sound installation work capable of sustaining interest for a minimum of 8 minutes.