Bob Cornford-Wood
One aspect of composing with AMPLE not mentioned in the feature in
AMPLINEX 004, was that of using the computer as a means to generate its own
music, rather than just reproduce an arrangement.
My program 'Randomination' is an attempt to do just this.
Before describing the program, it might be worth considering
the (probably unanswerable) question "What is music?" For John Cage's
5 minutes 33 seconds (of silence), music is the ambient noise of the audience
and concert hall. For most of us brought up in Western musical traditions, it can
be considered as an organised collection of rhythms, pitches and timbres -
usually conforming to the tonal system. How one actually organises these
elements determines one's acceptance of the piece as music or as noise.
What I am leading up to is - don't approach 'Randomination'
with a tonal (i.e. traditionally Western) frame of mind. Some people might
consider it meaningless sound - but it is an organised collection of rhythm,
pitch, timbre, dynamics, and spatial sound. I think it IS music (though not, by
any means GREAT music!), and as such worth listening to. It is something that AMPLE
might have been created to do!
The program uses 8 players which play one of three basic
types of note generator. 'rhythm' is the basic word which generates patterns
falling on exact subdivisions of the beat (which is supplied as a number).
'rndseq' is a variation of this where the 'hit' is replaced by selection of
another note. The recursive nature of these words (necessary to fill the beat
with notes or hits adding up to the right length) produces repetitive notes if
the first generated duration is not equal to the supplied number.
Another variation on this is 'rndseq2', where the recursion
is made to 'rndseq', producing more note changes within the beat number supplied.
By altering the recursion to itself, note changes on every hit would be
achieved.
Two players do the random walk. Note intervals are never
more than 1 in each direction, and repetition of a note is allowed. The numbers
supplied to 'randwalk' are the starting pitch and number of notes to be
generated. These are played at a steady 'walking' rhythm.
An extension of this is 'fractal', where intervals, although
randomly selected, are biased to lower numbers. The numbers supplied are as for
'randwalk'.
To allow for changing textures, a variable 'pause' is built
in (in 4/4 bars) - the word is supplied with the minimum number of bars pause
required and with the range of the pause. Also, most parts have the ability to
change instruments, volume and stereo position.
The program will produce a different result each time it is
run. If you want to produce predictable results, the random number generator
will have to be seeded. A possible way of doing this might be to ask for a key
to be pressed and then take the ASCII number of the key as the seed. With
numbers available for all the alphanumeric and symbol sets, over 50 'preset'
runs could be incorporated into the program.
Other refinements could take the form of restricting mix
changes for individual players (to ensure that the instruments suit the note
ranges), and giving 'randwalk' and 'fractal' notes varying rhythmic patterns.
I think that the fractal aspect could be considered further.
By making 'fractal' recursive on a number of levels, a musical equivalent of
the Mandelbrot Set might be constructed - each generated note being the
starting note for the next recursive call. Does anyone know how many levels of recursive
calls AMPLE can handle?
Lastly, the title. Why 'Randomination'? Played through the Mixing
Desk, the piece produces random animation, though the less charitable among you
might have thought it stood for 'random abomination'!
I would be happy to hear of any developments of the ideas in
this program, even if you only incorporate one stochastic element into an otherwise
'normal' program. Perhaps you could specify a chord progression and get AMPLE
to generate its own improvisation?
Happy tinkering!
Related file on this disc:
Published in AMPLINEX 005, May 1988
