Set MIDI output

Useful for instance when using PangoScript with a MIDI input device, to control its LEDs.

midiout [status byte],[control ID],[level 0-127 or 0x00 - 0x7f];

Setting the level of an output from its input value

e.g. a rotary dial that is used to adjust level which has indicators around it to show the current level

midiout 0xB0,0x15,extvalue (0,0x7f)