SuperCollider CLASSES


stream reference definition
Subclasses: Pbindef


Pdef is a class that provides an interface to its superclass EventPatternProxy, keeping a reference to a stream that can be replaced while playing. One pattern may be used in many streams in different places. A change in the pattern definition propagates through all streams.

Pdef and Pdefn use separate global collections.

Pdef(key)    //returns the instance
Pdef(key, pat)    //stores the pattern and returns the instance, like Tdef and Ndef.

It can be used to store event Patterns globally. Changes in this global library have immediate effect.

For non-event patterns Pdefn is used instead. For another use of Pdef see also recursive_phrasing. Graphical overview over all current Pdefs: PdefAllGui. Overview: JITLib.

First Example


Pdef(\x, Pbind(\note, Pbrown(0, 6, 0.1, inf)));
Pdef(\x).quant = 0; // no waiting.
Pbindf(Pdef(\x), \dur, 0.03).play;
Pbindf(Pdef(\x), \dur, 0.1, \ctranspose, 15).play;
Pbindf(Pdef(\x), \dur, 0.3, \ctranspose, 2).play;
// now change the definition
Pdef(\x, Pbind(\note, Pseq([0, 3, 5, 7, 9, 11], inf)));
Pdef(\x, Pbind(\freq, Pseq([1000, 1923, 245.2, 1718] / 1.2 + 0.1, inf)));

Class Methods


*new (key, item)

Store the pattern in a global dictionary under key, replacing its pattern with the new one. If the pattern is a function, Pdef creates a PlazyEnvir internally that dynamically creates the pattern returned from the function, applying the arguments from the inevent.

Using *new(key) you can access the pattern at that key (if none is given, a default silent event is created)

SynthDef(\Pdefhelp, { arg out, freq, sustain=1, amp=1, pan;
    var env =, sustain), 1, doneAction:2);,, 0.5pi, amp * env), pan));

// event pattern as an argument
Pdef(\x, Pbind(\instrument, \Pdefhelp, \note, Pbrown(0, 6, 0.1, inf), \dur, 0.2));
Pdef(\x); // omitting the second argument, we can access the proxy
Pdef(\x).play; // ... play one event stream
Pdef(\x).source.postcs; // ... and inspect the event pattern itself.

// function as an argument, create a new pattern each time it is called
Pdef(\x, { Pbind(\note, Pseries(10.rand, 5.rand, 8.rand + 1), \dur, 1 / (8.rand + 1)) });

// the function is called in the incoming event as current environment, so parameters can be passed:
Pdef(\stut, { Pstutter(~stutter ? 1, ~pattern) });
Pdef(\x, Pbind(\instrument, \Pdefhelp, \note, Pseq([0, 4, 7, 3, 0, 1, 0], inf)));
Pdef(\y, Pdef(\stut) <> (pattern: Pdef(\x), stutter: Pseq([2, 2, 4, 3], inf)) <> (dur: 0.1, legato: 0.2)).play;


From superclass: TaskProxy

Default source, if none is given. The default is an Event.silent of 1.0 beat duration.


From superclass: PatternProxy

Remove all proxies from the global dictionary ( *all )


From superclass: PatternProxy

Clear all proxies, setting their source to silence.


*all = value

Set or return the environment ( IdentityDictionary ) that stores all Pdefs.


*defaultQuant = value

From superclass: EventPatternProxy

Set the default quantisation for new instances (default: 1.0). This can be an array [quant, phase, timingOffset, outset]

Inherited class methods

Undocumented class methods

*gui (numItems, bounds, preset)

From extension in /usr/local/share/SuperCollider/SCClassLibrary/JITLib/GUI/


Instance Methods

Changing the definition / setting the source

One pattern may have many streams in different places. A change in the pattern definition Pdef propagates through all streams. The change does not have to be immediate - there is a scheme to schedule when the change becomes effective: a quant and clock (like elsewhere) and a condition.


-quant = val

From superclass: PatternProxy

Set the quantisation time for beat accurate scheduling.



can be an array [quant, phase, timingOffset, outset], or just [quant, phase] etc.


-condition = value

From superclass: PatternProxy

Provide a condition under which the pattern is switched when a new one is inserted. The stream value and a count value is passed into the function.

-count (n: 1)

From superclass: PatternProxy

Create and update condition that simply counts up to n and switches the pattern then


From superclass: PatternProxy

Switch the pattern immediately (stuck conditions can be subverted by this).


-fadeTime = value

From superclass: EventPatternProxy

When the synthdefs that are used contain an \amp control, the patterns are replaced by crossfading the previous with the new over this time (in beats)


-envir = dict

From superclass: PatternProxy

Set the event for the Pdef. It is used to filter the incoming stream before it is passed to the source pattern. This is similar to NodeProxy: -nodeMap. When set for the first time, the pattern is rebuilt.

-set ( ... args)

From superclass: PatternProxy

Set arguments in the default event. If there is none, it is created and the pattern is rebuilt.

-map ( ... args)

Map Pdefn to the keys in the event.


From superclass: PatternProxy

Set the source to nil

-endless (default)

From superclass: PatternProxy

Returns a Prout that plays the proxy endlessly, replacing nil with a default value (silent event). This allows to create streams that idle on until a new pattern is inserted.

Pdef as stream reference

A single Pdef may serve as a definition for multiple streams. These methods show how to fork off separate streams from one instance. Even if they run in different contexts, their definition may still be changed.

-fork (argClock, quant, protoEvent)

From superclass: EventPatternProxy

Play an independent stream in parallel.



The clock to run the substream on.


can be an array of [quant, phase, offset], or a Quant value.


An Event to pass in that is used by the substream


-embed (val)

From superclass: PatternProxy

Pass a value (typically an Event) into the pattern inval, and embed the Pdef in the stream.

embedInStream just like any pattern, embeds itself in stream

Pdef as EventStreamPlayer

For live coding, each Pdef also may control one instance that plays one stream off it. This is an EventStreamPlayer, accessible in the instance variable -player.

-play (argClock, protoEvent, quant, doReset: false)

From superclass: EventPatternProxy

Starts the Pdef and creates a player. (See: EventPatternProxy: -play)


From superclass: TaskProxy

Stops the player


From superclass: TaskProxy

Return the current player (if the Pdef is simply used in other streams this is nil)


From superclass: TaskProxy

-resume (clock, quant)

From superclass: TaskProxy


From superclass: PatternProxy

Perform this method on the player.


From superclass: TaskProxy

Returns true if player is running. If a Pdef is playing and its stream ends, it will schedule a stream for playing as soon as a new one is assigned to it. If it is stopped by stop, it won't.

Inherited instance methods

Undocumented instance methods

-copy (toKey)

-gui (numItems, bounds, preset)

From extension in /usr/local/share/SuperCollider/SCClassLibrary/JITLib/GUI/


-prAdd (argKey)


Pdef as stream reference

SynthDef("Pdefhelp", { arg out, freq, sustain=1, amp=1, pan;
    var env, u=1;
    env =, sustain), 1, doneAction:2); { var d; d = exprand(0.01, 1); u = * 300, u, rrand(0.1,1.2) * d, 1) };, + 1 * freq, 0, amp * env), pan));


Pdef(\metronom, Pbind(\instrument, \Pdefhelp, \dur, 1, \degree, 16, \legato, 0.1)).play;

x = Pseq([Pdef(\a), Pdef(\b), Pdef(\c)], inf).play;

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.25, \degree, Pseq(#[0, 5, 4, 3])));
Pdef(\b, Pbind(\instrument, \Pdefhelp, \dur, 0.125, \degree, Pseq(#[7, 8, 7, 8])));
Pdef(\c, Pbind(\instrument, \Pdefhelp, \dur, 0.25, \degree, Pseq(#[0, 1, 2], 2)));

Pdef(\c, Pbind(\instrument, \Pdefhelp, \dur, 0.25, \degree, Pseq(#[4, 3, 1, 2]*3)));

// infinite loops are scheduled (to ths clock's next beat by default) and released:

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.753, \degree, Pseq(#[0, 5, 4, 3, 2], inf)));
Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.125, \degree, Pseq(#[0, 5, 4, 3] + 1, 1)));
Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.25, \degree, Pseq(#[0, 5, 4, 3] - 4, 1)));

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.125, \degree, Pseq(#[0, 5] - 1, 1)));
Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.753, \degree, Pshuf(#[0, 5, 4, 3, 2], inf)));


// Pdef can be used in multiple patterns:

x = Ppar([
    Pbindf(Pn(Pdef(\a), inf),
        \gtranspose, Pstutter(8, Pseq(#[0, 2, 0, 3],inf))
    Pbindf(Pn(Pdef(\a), inf),
        \gtranspose, Pstutter(8, Pseq(#[7, 4, 0, 3],inf)),
        \dur, 0.6
    Pbindf(Pn(Pdef(\a), inf),
        \degree, Pseq(#[0, 5, 4, 3, 2, 3, 2], 1)

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.1, \degree, Pseq(#[0, 1, 0, 1, 2], inf)));

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.2, \degree, Pseq([0, 4], inf)));

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 1, \degree, Pseq([0, 4], inf)));

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.2, \degree, Pseq([0, 4, Prand([6, 8b],2)], inf)));

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.1, \degree, Pseq(#[0, 1b, 1, 2b, 2, 3, 4b, 4, 5], inf)));

// using a fade time, the above changes are crossfaded
Pdef(\a).fadeTime = 2;

Pdef(\a, Pbind(\instrument, \Pdefhelp, \dur, 0.2, \degree, Pseq([0, 4, Prand([6, 8b],2)], inf)));

// ...

Pdef(\a).set(\detune, -50); // set environment
Pdef(\a).set(\detune, 0);


Pdef as EventStreamPlayer

// load a synthdef
    { arg out=0, freq=440, sustain=0.05, amp=0.1, pan;
        var env;
        env =, sustain), doneAction:2) * amp;,, 0, env), pan))

Pdef(\x); // creates a Pdef with a default pattern.

Pdef(\x).play; // play it. A silent resting pattern is used.
Pdef(\y).play; // play a second one (automatically instantiated)

// assign various patterns to it:

Pdef(\x, Pbind(\dur, 0.25, \instrument, \gpdef));
Pdef(\x, Pbind(\dur, 0.25, \degree, Pseq([3, 4, 5b, 6], inf), \instrument, \gpdef));
Pdef(\x, Pbind(\dur, 0.25, \degree, Pseq([3, 4, 5b, 6]+1, inf), \instrument, \gpdef));
Pdef(\y, Pbind(\dur, 0.25, \degree, Pseq([3, 4, 5b, 6]-1, inf), \instrument, \gpdef));
Pdef(\y, Pbind(\dur, 0.25, \degree, Pseq([3, 4, 5b]-2, inf), \instrument, \gpdef));

// using fadeTime:

Pdef(\y).fadeTime = 8.0;
Pdef(\y, Pbind(\dur, 0.125, \degree, Pseq([3, 4, 5b, 6]+4.rand, inf), \instrument, \gpdef));
Pdef(\y, Pbind(\dur, 0.25, \degree, Pseq([3, 4, 5b, 6]-2, inf), \instrument, \gpdef));

Pdef(\x, Pbind(
        \dur, 1 / 6,
        \degree, Pseq([3, 4, Prand([8, 2, 3, 9, 10],1) - 5, 6]+1, inf),
        \instrument, \gpdef
Pdef(\x, Pbind(
        \dur, 0.25,
        \degree, Pseq([3, 4, Prand([8, 2, 3, 9, 10],1), 6], inf),
        \instrument, \gpdef)


// tempo change
TempoClock.default.tempo = 1.3;
Pdef(\y, Pbind(\dur, 0.25, \degree, Pseq([3, 4, 5, 6]+1, inf), \instrument, \gpdef));

// drop in ending patterns

Pdef(\x, Pbind(\dur, 0.25, \degree, Pseq([3, [7,4], 5, 6]-2), \instrument, \gpdef));
Pdef(\x, Pbind(\dur, 0.125, \degree, Pseq([3, [7,4], 5, 4]-3), \instrument, \gpdef));
Pdef(\x, Pbind(\dur, 0.35, \degree, Pseq([3, [7,4], 5, 4, 3]-3), \instrument, \gpdef));
Pdef(\x, Pbind(\dur, 0.25, \degree, Pshuf([3, [7,4], 5, 6]-2), \instrument, \gpdef));

// clear all.
TempoClock.default.tempo = 1.0;

// GUI example: see also


Pdefs can be used recursively under the condition that the stream call structure allows it. a structure like the following works:

Pdef(\x, Pseq([Pbind(\instrument, \gpdef), Pdef(\x)], inf));

but the following would crash, because .embedInStream is called recursively with no limit:

// Pdef(\y, Pseq([Pdef(\y), Pbind(\instrument, \gpdef)], inf));

Quantizing and outset

When quantizing to a larger number of beats, the changes become very slow if one has to wait for the next beat. Providing an outset quant value is a way to make the change so that it appears as if it had been done at the previous grid point already. The stream is fast forwarded to the current position relative to the quant grid. Providing a number larger than zero, the next possible quant point is used as outset.

For example, if quant is 32, and one has just missed the first beat when changing the pattern, one has to wait for 32 beats until the change happens. Using an outset of 1, it is assumed that you had already changed the pattern at the first beat, the stream is fast forwarded to the time it would be at now if you had done so. The new pattern is inserted at the next beat (outset=1).

quant can be: [quant, phase, timingOffset, outset]

NOTE: This fast forwarding might create a cpu peak if the pattern is very complex/fast or quant is very long. This is hard to avoid, so it simply has to be taken into account.
Pdef(\x).quant_([8, 0, 0, 1]);
Pdef(\y).quant_([8, 0.5, 0, 1]); // phase: half a beat

Pdef(\x, Pbind(\degree, Pseq((0..7)+2, inf)));
Pdef(\y, Pbind(\degree, Pseq((0..7)-2, inf)));
Pdef(\x, Pbind(\degree, Pseq((0..7)+2, inf), \dur, 0.5));
Pdef(\y, Pbind(\degree, Pseq((0..7).scramble-2, inf), \dur, 0.25, \legato, 0.3));
Pdef(\x, Pbind(\degree, Pseq((0..7), inf)));

Pdef(\x, Pbind(\degree, Pseq([ 1, 5, 6, 7, 0, 3, 2, 4 ], inf), \dur, 1));
Pdef(\x, Pbind(\degree, Pseq([ 0, 2, 2, 4, 0, 4, 0, 4 ], inf), \dur, 1));

Pdef(\x).quant_([8, 1/3, 0, 1]); // phase: 1/6 beat relative to y
Pdef(\x, Pbind(\degree, Pseq([ 1, 1, 1, 7, 0, 2, 2, 4 ], inf), \legato, 0.1));
Pdef(\x, Pbind(\degree, Pseq([ 3, 3, 3, 4b ], inf), \legato, 0.1));
Pdef(\y, Pbind(\degree, Pseq((0..7).scramble-4, inf), \dur, 0.25, \legato, 0.3));

// some testing
var quant = #[8, 0, 0, 1]; // quantise to 8 beats, no phase, insert quant to 1 beat
Routine { loop { { |i| ("uhr:"+i).postln; 1.wait } } }.play(quant:quant);
Pbind(\degree, Pseq((0..7), inf)).play(quant:quant);

Pdef(\x, Pbind(\degree, Pseq((0..7)+2, inf)).trace(\degree));
Pdef(\x, Pbind(\degree, Pseq((0..7), inf) + [0, 3]).trace(\degree));
Pdef(\x, Pbind(\degree, Pseq((0..7), inf) + [0, 6], \dur, 0.5).trace(\degree));

Pdef(\x).fadeTime = 8;

Pdef(\x, Pbind(\degree, Pseq((0..7), inf)).trace(\degree));
Pdef(\x, Pbind(\degree, Pseq((0..7).reverse, inf) + [0, 6], \dur, 0.5));

Pdef(\x).fadeTime = nil;
Pdef(\x).quant = 1;

Pdef(\x, Pbind(\degree, Pseq((0..7), inf)).trace(\degree));

Pdef(\x).quant = 8;
Pdef(\x, Pbind(\degree, Pseq((0..7), inf)).trace(\degree));

Update condition

In order to be able to switch to a new pattern under a certain -condition, the instance variable condition can be set to a function that returns a boolean. Value and a count index are passed to the function. The condition is always valid for the next pattern inserted. For stuck conditions, the -reset message can be used.

As counting up (such as "every nth event, a swap can happen") is a common task, there is a method for this, called -count(n).

Pdef(\x).quant = 0; // we don't want quant here.
Pdef(\x, Pbind(\degree, Pseq((0..5), inf), \dur, 0.3)).condition_({ |val, i| i.postln % 6 == 0 });
Pdef(\x, Pbind(\degree, Pseq((0..7) + 5.rand, inf), \dur, 0.3)).condition_({ |val, i| (i % 8).postln == 0 });

// the above is equivalent to:
Pdef(\x, Pbind(\degree, Pseq((0..7) + 5.rand, inf), \dur, 0.3)).count(8);

// the value that is sent in is the event, so decisions can be made dependent on the event's fields


// reset to change immediately: