Friday, May 11, 2018

Panola: a supercollider PAttern NOtation LAnguage

Problem?

In supercollider, one of the best ways to schedule notes over time is by using the pattern system. The pattern system is very flexible but the flexibility can make it a bit hard to use. 

In a typical pattern specification, also known as a Pbind, every dimension to your sound event is independent from every other event. This is just a fancy way of saying that you need to specify volume separately from duration, separately from midinote, etc.

If you want to delete a note in the middle of your piece, you have to dig through all these keys in the pattern specification to find the right stuff to remove or add so as to make sure that all the rest still sounds as intended.

Solution?

By grouping all musical information together and extracting the required keys from that central specification, we can change information in one place and keep all the resulting keys in sync automatically.

Thinking about this, I thought back of a creation I made last year: the midi specification language (MISPEL, see https://github.com/shimpe/expremigen ). I dreamed about having this system available in supercollider. I didn't quite get there yet, but now at least a subset of Mispel is available in supercollider and that subset is known as Panola (pattern notation language), available from https://github.com/shimpe/panola 

Tutorial?

(For now this is a literal copy of the tutorial on http://sccode.org/1-5aq - feel free to go there, it has syntax coloring :) )

// Panola is a way to extract Pbind keys from a concise specification.
// This makes it easier to compose "traditional" music with Pbind, with a lot less
// headache trying to keep the different keys in sync
// It's the type of system I've missed since my day one with supercollider.

// First things first. To install Panola:

Quarks.install("https://github.com/shimpe/panola");

// Now you can get the help document by typing ctrl+D with the cursor on the word
// Panola in the next line

Panola.new("a4");

// Let's start with the "Hello world" of Panola: a simple scale.
// The numbers indicate octaves.
// You don't need to repeat octave numbers if they don't change between notes.
(
~ex = Panola.new("c4 d e f g a b c5");
~player = ~ex.asPbind.play;
)

// asPbind takes a synth name as parameter (which defaults to \default).
// So the above is equivalent to
(
~ex = Panola.new("c4 d e f g a b c5");
~player = ~ex.asPbind(\default).play;
)

// instead of calling a single "asPbind" you can also extract all information separately
// like this you have optimal flexibility in what you want to use from Panola
(
~ex = Panola.new("c4 d e f g a b c5");
~pat = Pbind(\instrument, \default, \midinote, ~ex.midinotePattern, \dur, ~ex.durationPattern, \amp, ~ex.volumePattern, \tempo, ~ex.tempoPattern, \lag, ~ex.lagPattern, \legato, ~ex.pdurPattern);
~player = ~pat.play;
)

// You can make chords using angular brackets. Only note properties of the first
// note in the chord (other than octave number and note modifier (see later)) are
// taken into account.
(
~ex = Panola.new("<c4 e> <e g> <c e g c5>");
~player = ~ex.asPbind.play;
)

// You can use modifiers on the notes:
// # for sharp, x for double sharp, - for moll, -- for double mol
(
~ex = Panola.new("c4 d- e f# gx a# b-- c5");
~player = ~ex.asPbind.play;
)


// With underscores you can indicate rhythm.
// The last used rhythm value is reused until a new one is specified:
// Here's four quarter notes (_4) followed by four eighth notes (_8).
(
~ex = Panola.new("c4_4 d e f g_8 a b c5");
~player = ~ex.asPbind.play;
)

// You can use one or more dots to extend the length of the rhythm, as in traditional notation.
(
~ex = Panola.new("c4_4. d_8 e_4 f g_16 a_4.. b_4 c5");
~player = ~ex.asPbind.play;
)

// You can also use multipliers and/or dividers to change the length.
// E.g. here we use it to create a note that lasts for three eighths
// (c4_8*3) and to create tuplets (e_8*2/3 f g). Remember that last
// duration/rhythm indication is reused until a new one is specified.
(
~ex = Panola.new("c4_8*3 d_8 e_8*2/3 f g f_16 e f e g_4 b_4 c5");
~player = ~ex.asPbind.play;
)

// Now we come to the animated property system. We can attach properties to the notes and animate them over time.
// For now two types of animation are supported: linear interpolation and fixed value.
// To indicate linear interpolation, use curly brackets {}. E.g. here we let the tempo gradually increase from 80 bpm to 160 bpm:
(
~ex = Panola.new("c4\\tempo{80} d e f g a b c5\\tempo{160}");
~player = ~ex.asPbind.play;
)

// Different properties can be combined. Here we let the volume go up until the middle of the phrase, then let it go down again,
// while tempo is rising from 80 bpm to 160 bpm.

(
~ex = Panola.new("c4\\tempo{80}\\vol{0.2} d e f g\\vol{0.9} a b c5\\tempo{160}\\vol{0.2}");
~player = ~ex.asPbind.play;
)

// If you want to use the fixed values, use square brackets instead. You can switch between fixed and animated everytime
// you specify a new property value. In the next example, tempo remains at 80 bpm until we come to note a. At that point,
// it jumps to value 100 bpm and gradually increases to 200.
(
~ex = Panola.new("c4\\tempo[80] d e f g a\\tempo{100} b c5 d e f g a b c6\\tempo{200}");
~player = ~ex.asPbind.play;
)

// Using pdur (think: played duration), we can indicate the difference between staccato and legato.
// Here we slowly evolve from very staccato to very legato:
(
~ex = Panola.new("c4_8\\pdur{0.1} d e f g a b c5 d e f g a b c6\\pdur{1}");
~player = ~ex.asPbind.play;
)

// Using lag we can modulate lag. This can be a way of creating a rubato feeling.
// Linear interpolation is not ideal for this purpose, but it's better than nothing at the moment.

(
~ex = Panola.new("a5_8\\tempo[120]\\lag{0} b c6 a5 e d c5 d e c a4 g#4\\lag{0.5} "
"a4_8 b c5 a4 e d c4 d e c a3 g#3 a b c4 d e g# a_2\\lag{0}");
~player = ~ex.asPbind.play;
)

// In addition to using predefined properties like tempo and lag, you can also use user
// defined properties, e.g. here we animate a property called "myprop".
(
~phrase = Panola.new("c d\\myprop{0.1} e f g a\\myprop{0.6}");
~pattern = ~phrase.customPropertyPattern("myprop"); // extract only myprop values as a pattern
~stream = ~pattern.asStream;
10.do({
| i |
~stream.next.postln;
});
)
// make a pbind in which the myprop appears as one of the keys, with a default value of 0 for myprop
(
~pbind = ~phrase.asPbind(\default);
~stream = ~pbind.patternpairs[13].asStream;
10.do({
| i |
~stream.next.postln;
});
)
// make a pbind in which the myprop appears as one of the keys, with a customized default value of 0.4 for myprop
// (such default values are used if no values for myprop are specified yet, e.g. in the beginning of a Panola string,
//  before any myprop is defined).
(
~pbind = ~phrase.asPbind(\default, custom_property_defaults:Dictionary.newFrom(["myprop", 0.4]));
~stream = ~pbind.patternpairs[13].asStream;
10.do({
| i |
~stream.next.postln;
});
)
// make pbind in which only the standard panola keys are included
(
~pbind = ~phrase.asPbind(\default, include_custom_properties:false);
~pbind.patternpairs.postln;
)

// These custom properties can be e.g. used to drive synth arguments
// The 303 synth used below is reused from https://sccode.org/1-4Wy
// which in turn is based on code from Lance J. Putnam
(
s.waitForBoot({
var line;

SynthDef (\sc303 , {  arg  out=0, freq=440, wave=0, ctf=100, res=0.2,
sus=0, dec=1.0, env=1000, gate=1, vol=0.1;
var  filEnv, volEnv, waves;
volEnv =  EnvGen .ar( Env .new([10e-10, 1, 1, 10e-10], [0.01, sus, dec],  'exp' ), gate, doneAction:2);
filEnv =  EnvGen .ar( Env .new([10e-10, 1, 10e-10], [0.01, dec],  'exp' ), gate);
waves = [ Saw .ar(freq, volEnv),  Pulse .ar(freq, 0.5, volEnv)];
Out .ar(out,  RLPF .ar(  Select .ar(wave, waves), ctf + (filEnv * env), res).dup * vol);
}).add;

s.sync;

line = Panola.new(
"a2_16\\wave[0]\\vol{0.05}\\tempo{120}\\res{0.2}\\sus{0}\\env{1000}\\ctf{100} a a a1 a2 a a3 a2 a a a1 a2 a3 a2 b- g\\res{0.05}"
"a2_16\\wave[0] a a a1 a2 a a3\\sus{0.2} a2 a\\ctf{3000} a a1 a2 a3 a2 b- g\\res{0.2}"
"a2_16\\wave[0] a a a1 a2 a a3 a2 a a a1 a2 a3 a2 b- g\\res{0.01}\\sus{0}\\env{10000}\\ctf{10}"
);
~player = line.asPbind(\sc303).play;
});
)

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