I found a MIDI Controller called "Hold pedal 2" (0d69 or 0x45). What is this? Is it important or useful?
The MIDI Hold 2 message (Controller 69, 0-63 for off, 64-127 for on) lengthens the release time of the playing note´s VCA (i.e. makes the note take longer to fade out after it's released). The note may still eventually fade out.
In contrast the standard Hold 1 (or Sustain, Controller 64) message lengthens the sustain section of the playing note´s VCA. A message with an on value (64-127) postpones any Note Off messages on the same channel until it is turned off (value 0-63). This is similar to the function of the hold pedal on an acoustic piano.
Whether this useful or not is up to the player to decide. Not all hardware or software devices implement the function (the details of the MIDI implementation are normally in the manual).
Can you explain the difference between CC 64 (Hold 1 / Sustain pedal) and CC 69 (Hold 2)? Aug 17, 2022 at 10:10
@ElementsinSpace I assumed everybody knows what the sustain message does. Aug 17, 2022 at 15:01
Yeah, it's just that the Hold 2 seems more like the effect that a real piano has, as opposed to Hold 1 (which apparently doesn't decay). Aug 17, 2022 at 15:12
@ElementsinSpace For a piano or percussion sound Hold 1 already does what´s needed (at least on any device I´ve ever seen).. For those sounds Hold 2 makes no sense. Note the messages work differently: Hold 2 affects device parameters, Hold 1 works at the MIDI message level. Aug 17, 2022 at 16:44
@ElementsinSpace Since the MIDI spec for Hold 2 refers to VCAs it seems that the message is only intended for synths with an ADSR envelope. Aug 17, 2022 at 16:58
Thinking in terms of an ADSR envelope, Hold 1 (Sustain) prolongs the Sustain portion, delaying the start of the Release portion. Hold 2 extends the Release.
But that's just the conventional historical use. Like any MIDI controller, they can be assigned to any parameter of the sound whatsoever. Hold 1 (Sustain) makes sense for just about any sound (though some over-zealous Organ emulations don't recognise it) so you can be pretty confident Controller 64 will prolong the note. Controller 69 is more up for grabs. If I was programming a realistic vocal sound, I might use it to switch in the vibrato that singers often bring in half-way through a long note. Or I might use it to switch in an echo or reverb effect.
(Should a piano patch use Controller 64 or 69? It's a theoretical question - they always DO use Controller 64. But do you see why I ask?)
There are more appropriate continuous controllers for effects: controller 91 is reverb send. There are also the general purpose controllers 16 to 19. Aug 17, 2022 at 22:03
Yup. Spoiled for choice, aren't we!– LaurenceAug 17, 2022 at 23:37