MidiInput.plug(Object _object, String _methodName, int channel, int value)
Object _object: Callback object
String _methodName: Name of the method of the callback object that will be called by the input
int channel: Channel of the message, -1 for all channels
int value: MIDI status byte, -1 for all messages
Register a callback method on a specific channel for a specific MIDI command. The value field is the MIDI status byte, for example 0x90 for NOTE ON.