snd_opl3_drum_switch
snd_opl3_drum_switch(opl3, note, vel, 1, chan);
snd_opl3_drum_switch(opl3, note, vel, 0, chan);
void snd_opl3_drum_switch(struct snd_opl3 *opl3, int note, int vel, int on_off, struct snd_midi_channel *chan);