Killer Game Programming in Java

MIDI Synthesis

I'll consider three approaches to synthesizing MIDI sound at runtime:

• Send note-playing messages to a MIDI channel. The MidiChannel class offers noteOn() and noteOff() methods that transmit NOTE_ON and NOTE_OFF MIDI messages.

• Send MIDI messages to the synthesizer's receiver port. This is a generalization of the first approach. The advantages include the ability to deliver messages to different channels, and the ability to send a wider variety of messages.

• Create a sequence, which is passed to the sequencer. This is a generalization of the second approach. Rather than send individual notes to the synthesizer, I build a complete sequence.

These approaches are labeled in the MIDI devices diagram in Figure 10-4.

Figure 10-4. Different MIDI synthesis approaches

Tip

There is a good Java Tech Tip on these topics at http://java.sun.com/jdc/JDCTechTips/2003/tt0805.html.

Sending Note-Playing Message to a MIDI Channel

The MidiChannel class offers noteOn() and noteOff() methods that correspond to the NOTE_ON and NOTE_OFF MIDI messages:

    void noteOn(int noteNumber, int velocity);
    void noteOff(int noteNumber, int velocity);
    void noteOff(int noteNumber);

The note number is the MIDI number assigned to a musical note, and velocity is equivalent to the loudness. A note will keep playing after a noteOn() call until it's terminated with noteOff(). The two-argument form of noteOff() can affect how ...