(sonicarts) midi with a limited focus

Since we are only working with MIDI for a short time in this class, we will keep our focus on a very limited set of MIDI commands:

  • Noteon/Noteoff
  • Continuous Controller
  • Pitch Bend

Noteon/Noteoff messages include data for the number of the MIDI note pressed, and the velocity that it was pressed with. Keep in mind that although software may display MIDI note number as a pitch, the computer stores the information as a number. Most of us think of how hard we press a key (or hit a drum), but MIDI measures how fast we press the key. It’s cheaper to detect than force.

Pitch Bend sends a command that corresponds to the amount of deviation, or movement of the pitch bend wheel/joy stick. The actual pitch deviation is determined by that data being applied to the pitch bend maximum range that is usually set for each synthesizer program (or patch). The pitch bend control sends a percentage of change, which is then applied to the maximum possible value on the receiving end.

Continuous Controller (CC) messages are intended to be used to send performance control information while a note is being held. There are a maximum possible 128 continuous controllers, but in practice only a small subset are used. The most common:

  • 1: Mod Wheel
  • 2: Breath Control
  • 7: Volume
  • 10: Pan
  • 64: Sustain (a switch, 0 – 63 = off; 64 – 127 = on)

MIDI devices don’t have to respond to all of these controllers, nor do they have to send these CC numbers to represent the specified data types listed. The five listed values, however, are commonly used for the listed functions. Software may mask the CC number and simply show your the associated name.