From Brian Willoughby Sent Mon, Oct 8th 2018, 22:28
On Oct 8, 2018, at 2:50 PM, Scott Fox <xxxxxxxxx@xxxxx.xxx> wrote: > Mode 4 allows you to pitchbend just one note of, say, 5 notes played? = A stable low chord and pitch vibrato on a single high note without = affecting the others? It's my understanding that mode 4 still shares a = common pitchbend. If I'm wrong, please correct me.=20 >=20 > This is something I use constantly when working with MPE. MIDI has 16 channels. That means you have 16 Pitch Bend messages. Things = must be coordinated between the controller and the synth. If the = controller assigns a different channel to each note, which is what both = Mode 4 and MPE do, then you=E2=80=99ll have a unique Pitch Bend for each = note. The message that puts a receiver into Mode 4 is itself on a channel = number, but that merely sets the Base Channel. Mode 4 can either specify = the number of voices, up to 16, or it can specify =E2=80=9C0=E2=80=9D to = ask for all of the voices of the receiver. Starting at the Base Channel, = each next channel controls the next voice, and changes (including bend) = for each note should have a different channel. There is a Global Controller channel, which is one below the Mode 4 Base = channel, that is used for controls that affect all notes. If you have = one Pitch Bend wheel on a physical polyphonic expression controller, = it=E2=80=99s most likely that moving the one bend wheel will be sent on = the Global Controller channel and affect all notes, since there=E2=80=99s = no way for the controller to know which individual note you intended it = for. However, if you assign pitch to some movement of an individual key = - such as pressure or X or Y position - then this control change message = should be sent on the channel that is active for that note. MPE is almost exactly the same, except that the Master Channel is the = first channel, rather than one below that. In fact, MPE is limited to 15 = polyphonic channels, since control changes on the 1st channel are = defined as affecting all notes on all channels. Depending upon how an = MPE controller is set up, it can still have a single Pitch Bend wheel = that affects all notes in a chord if the Pitch Bend message is sent on = the Master Channel. So, yes, MIDI Mode 4 definitely supports a unique pitch bend for each = note. There=E2=80=99s basically no difference between Mode 4 and MPE here, = except for the numbering of the Global versus Master channels. Actually, = MPE is a little more explicit in pointing out the Master Channel, which = unfortunately reduces it to support only 15 voices, where Mode 4 allows = the Global Controller channel as a vague option, so you don=E2=80=99t = really know whether you have 16 voices and no Global Controls, or 15 = voices with Global Control. I get the impression that since MIDI Mode 4 was created in the days when = 5, 6, or 8 voices was about the most we ever expected, they didn=E2=80=99t= really think about the importance of stating with certainty whether the = Global Controller channel took away a voice. Strangely, given that MPE = is supposed to improve MIDI by being much more explicit about things, I = still get the impression that people don=E2=80=99t actually realize that = MPE is limited to 15 Member Channels. In other words, with a 16-voice = Moog One, you can=E2=80=99t actually have 16 independent pitch bends. = You can have 15, but not 16. In contrast, Mode 4 can do 16, but not = unless you set up both the controller and the synth to handle it. MPE = simplifies this by forcing the limit of 15. Of course, MPE still manages = to be vague by allowing an Upper Zone that reduces the limit of 15 to = even lower channel counts. Brian Willoughby