if (jack_midi_event_write (jack_buffer, when, ev, 3) != 0) {
cerr << "failed to deliver sustain-zero on channel " << channel << " on port " << name() << endl;
}
if (jack_midi_event_write (jack_buffer, when, ev, 3) != 0) {
cerr << "failed to deliver sustain-zero on channel " << channel << " on port " << name() << endl;
}