T.R | Title | User | Personal Name | Date | Lines |
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972.1 | Doesn't do anything with note on/offs. | MAY20::BAILEY | Steph Bailey | Mon Oct 05 1987 18:42 | 29 |
| Hunh? Do you mean what happens when you press the sustain pedal
on a keyboard?
It sends a a ``hold on'' message (control change of control number
64 to a value of 64). When you let it go it sends a control change
of control number 64 to 0.
It don't do nothing with the note ons or offs. Its just a binary
switch which the device is supposed to interpret.
Therefore if a sequencer wants to figure out where notes actually
end, for editing on a per-note basis, they have to make assumptions
about how a synth interprets the message (like that all notes struck
will hold until the pedal is released).
As a counter example to the traditional hold-pedal processing,
the Prophet T-8 and VS have two different release phases on their
envelopes, one which is used when the note is released and the hold
pedal is up, and the other one to use when the hold pedal is down.
I have never seen a sequencer which actually tried to figure out
when a note ended after factoring the hold pedal. The problem is
that you can't edit such notes very easily. Better to just show
where the hold starts and ends.
I hope this was what you were asking about..........
Steph
|
972.2 | | SALSA::MOELLER | | Mon Oct 05 1987 18:49 | 12 |
| I've examined the MIDI data stream both with Performer on the MAC
and the Emax' own 'MIDI Window' function. As far as I know you're
BOTH right. The only change to the MIDI stream is the insertion
of a 64/64 controller entry when depressed, and a 64/0 entry when
released.
As far as what happens within the synth, my impression is that
note-offs are suppressed, up to the synth's polyphony limit, and
if more notes are requested then its own 'stealing' algorithm is
invoked.
karl
|
972.3 | | SALSA::MOELLER | | Mon Oct 05 1987 18:54 | 13 |
| I've examined the MIDI data stream both with Performer on the MAC
and the Emax' own 'MIDI Window' function. As far as I know you're
BOTH right, just not communicating clearly. The only change to the
MIDI stream is the insertion of a 64/64 controller entry when
depressed, and a 64/0 entry when released. The note-off commands
ARE still sent.
As far as what happens within the synth, my impression is that
the note-offs are ignored, up to the synth's polyphony limit, and
if more notes are requested then its own 'stealing' algorithm is
invoked.
karl
|
972.4 | | JAWS::COTE | BddddttttYEEeeoowww! (C. Hynde) | Tue Oct 06 1987 08:58 | 5 |
| Of the 2 previous scenarios, it appears the suppressed note-off
idea is wrong. My DX faithfully sends Note-Offs even when the
sustain pedal is depressed.
Edd
|
972.5 | ... or was the pedal plugged in? ... | AKOV68::EATOND | The Mike Mongeon Band: 10/9, Holden | Tue Oct 06 1987 09:48 | 6 |
| RE < Note 972.4 by JAWS::COTE "BddddttttYEEeeoowww! (C. Hynde)" >
Not to insult your intelligence, Edd, but have you checked the DX's
controller parameters to be sure that some relavant switch hasn't been toggled?
Dan
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972.6 | 'course it was plugged in... | JAWS::COTE | BddddttttYEEeeoowww! (C. Hynde) | Tue Oct 06 1987 09:55 | 11 |
| No insult taken.
In case there's any confusion, I'm not having any problems, I'm
just curious as to *how* it works. All this time I assumed that
depressing the pedal just supressed note-offs, but when I had the
monitor on, there they were! Just like always. Which got me to
thinking....
Just an FMI type question. Can be FYI too.
Edd
|
972.7 | I remember asking this ... | AKOV68::EATOND | The Mike Mongeon Band: 10/9, Holden | Tue Oct 06 1987 10:36 | 8 |
| It's definately a control change accross the interface. When I got
the CZ101 and tried controlling it from a juno, the first big dissapointment
I had was that it (the CZ) wouldn't accept sustain hold from the pedal; only
sustain via holding down the keys. Looking on various MIDI implementation
charts I found MIDI sustain under the Control Change section. Needless to say,
it was ommitted on the CZ's chart.
Dan
|
972.8 | An analogy | DYO780::SCHAFER | Dragons is *so* stupid ... | Tue Oct 06 1987 12:09 | 16 |
| MIDI SUSTAIN (like any other MIDI command) is interpreted on a per
instrument basis, and processed accordingly. Kinda like a FORTRAN
READ statement - it may look the same in FORTRAN, but the machine code
varies by processor.
As for the SUSTAIN command, it simply tells a synth to "act like
someone pressed your sustain pedal". The reason this command does NOT
work on the CZ (or on pre MIDI synths that have MIDI retrofits) is
because the synth's processor (which is used to process MIDI protocol)
does not process its internal SUSTAIN command. In the case of the
OB-Xa, sustain is a seperate circuit.
There are probably as many different ways to directly answer your
question as there are synth manufacturers, Edd.
8^)
|
972.9 | how bout master volume? | JON::ROSS | Micro-11: The VAX RISC | Tue Oct 06 1987 14:08 | 12 |
| look, the kbd HAS to also send note offs, because it
could be a master controller to >1 synth.
The sustain messages (on, off) are distinctly separate
from note on/offs, and why not?
no problem. if your synth doesnt handle it. If the kbd
suppressed note offs, you could get stuck note ons on
a synth that had sustain disabled or such....
fun.
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972.10 | Voicing/MIDI Implentation Problems | SSDEVO::WESTBROOK | | Fri Oct 09 1987 16:20 | 36 |
|
Jim Cooper once hinted at making a box which would take your MIDI
keyboard control input as well as a footswitch input. It would
then supress the Note-Off events whenever the pedal was pressed,
sending them when the pedal was released. However, he never
released it because of problems with the way different synths
assign/deassign voices.
For example, suppose a four-voice box (e.g. Poly-800) was slaved
to this controller (you'd have to use a separate keyboard
controller unless your synth supported local on/off) and you
pressed the pedal and played a bunch of notes. Then you released
the pedal. A bunch of note-off events would be sent. However,
some synths would hang notes, because whenever they receive
note-off events for non-sounding notes, they get confused.
I encountered problems like this when designing the operating
code for Lync's LN-1 strap-on controller. We wanted to make sure
it wouldn't crash anybody's synths, no matter what the voice
capability or voice-stealing algorithm. Seems they all handled
it a little bit differently, and many completely ignored
commandments from the MIDI spec (does all-notes-off ring a
bell?).
Even Yamaha was bad about this. The old TX816 modules would hang
a note if too many note-on events arrived. Then, even after the
notes stopped sounding, the next time a note-on/off sequence
arrived for the same note, the note would hang again. They seem
to have fixed this in the later modules, though (especially in
the TX802 - - one of the better MIDI implementations I've seen,
especially with the multi-instrument capability and the problems
that could have arisen).
Well, enough rambling for now.
Eric
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