The 2nd midi in Processing example will use the Receiver interface to capture all the midi messages during the playback of a midi file. The program uses the custom GetMidi class to implement the Receiver interface. During the playback, it will display the NOTE_ON message with information of channel, octave and note.

The source code of the example is also in the Magicandlove GitHub repository.

This is my first use of midi in Processing. I do not use the MidiBus library for Processing. Instead, I try to use the standard midi package in Java. The SE8 standard Java package also contains the javadoc documentation.

The Processing source code and sample midi files are in the Magicandlove GitHub repository. The midi example files are downloaded from the midiworld website.

The code basically needs a Synthesizer class to render midi instruments into audio and a Sequencer class to playback the midi sequence.

Synthesizer synth = MidiSystem.getSynthesizer();
Sequencer player = MidiSystem.getSequencer();
synth.open();
player.open();

All the midi music files are in the data folder of the Processing sketch. To playback each piece of midi music, we need to convert each into a Java File object and use the following code to playback it. The variable f is a File object instance containing the midi file in the data folder.

Sequence music = MidiSystem.getSequence(f);
player.setSequence(music);
player.start();