core | ugens | analysis



The Instrument interface is expected by AudioOutput.playNote. You can create your own instruments by implementing this interface in one of your classes. Typically, you will create a class that constructs a UGen chain: an Oscil patched to a filter patched to an ADSR. When noteOn is called you will patch the end of your chain to the AudioOutput you are using and when noteOff is called you will unpatch.





  * This sketch demonstrates how to create synthesized sound with Minim using an AudioOutput and
  * an Instrument we define. By using the playNote method you can schedule notes to played 
  * at some point in the future, essentially allowing to you create musical scores with code. 
  * Because they are constructed with code, they can be either deterministic or different every time. 
  * This sketch creates a deterministic score, meaning it is the same every time you run the sketch.
  * <p>
  * For more complex examples of using playNote check out algorithmicCompExample and compositionExample
  * in the Synthesis folder.
  * <p>
  * For more information about Minim and additional features, visit

import ddf.minim.*;
import ddf.minim.ugens.*;

Minim minim;
AudioOutput out;

// to make an Instrument we must define a class
// that implements the Instrument interface.
class SineInstrument implements Instrument
  Oscil wave;
  Line  ampEnv;
  SineInstrument( float frequency )
    // make a sine wave oscillator
    // the amplitude is zero because 
    // we are going to patch a Line to it anyway
    wave   = new Oscil( frequency, 0, Waves.SINE );
    ampEnv = new Line();
    ampEnv.patch( wave.amplitude );
  // this is called by the sequencer when this instrument
  // should start making sound. the duration is expressed in seconds.
  void noteOn( float duration )
    // start the amplitude envelope
    ampEnv.activate( duration, 0.5f, 0 );
    // attach the oscil to the output so it makes sound
    wave.patch( out );
  // this is called by the sequencer when the instrument should
  // stop making sound
  void noteOff()
    wave.unpatch( out );

void setup()
  size(512, 200, P3D);
  minim = new Minim(this);
  // use the getLineOut method of the Minim object to get an AudioOutput object
  out = minim.getLineOut();
  // when providing an Instrument, we always specify start time and duration
  out.playNote( 0.0, 0.9, new SineInstrument( 97.99 ) );
  out.playNote( 1.0, 0.9, new SineInstrument( 123.47 ) );
  // we can use the Frequency class to create frequencies from pitch names
  out.playNote( 2.0, 2.9, new SineInstrument( Frequency.ofPitch( "C3" ).asHz() ) );
  out.playNote( 3.0, 1.9, new SineInstrument( Frequency.ofPitch( "E3" ).asHz() ) );
  out.playNote( 4.0, 0.9, new SineInstrument( Frequency.ofPitch( "G3" ).asHz() ) );

void draw()
  // draw the waveforms
  for(int i = 0; i < out.bufferSize() - 1; i++)
    line( i, 50 + out.left.get(i)*50, i+1, 50 + out.left.get(i+1)*50 );
    line( i, 150 + out.right.get(i)*50, i+1, 150 + out.right.get(i+1)*50 );


Web & Application