It sounds to me like you may have a MIDI Loop unintentionally set up - One way to see if this is what the problem is, is turn the blue Play Enable arrowhead in DP OFF for the Midi Track that you are Recording on. Then do what was causing the problem before. Did it go away?
Here's another way to do the same test:
Turn Local OFF on the Montage, but leave the blue Play Enable arrowhead in DP ON for the Midi Track that you are Recording on. Is the problem gone?

If my hunch is right (and Please Forgive Me if you know all this stuff, and I'm showing disrespect by even bringing it up!) - the Montage is INTERNALLY changing its Performance, but it's ALSO sending a Program Change over Midi, and then receiving it at its Midi IN, being echoed by DP. So it's glitching because it's getting the double commands, and maybe even echoing them back to DP AGAIN! (but if it were retransmitting them a 2nd time, you'd probably have a lot worse glitching going on - so that part's probably NOT happening.)

Good luck with it : ) PS> I really like DP myself, longtime user.

Try using only PARTs 1-8 and not 9-16. Seamless sound switching is only available when this condition is met. This may be related. Although your particular use case doesn't fit a model I'm familiar with - so there may be other limitations at play.

Michael wrote:

I've got a Montage 8 connected to a 27" iMac running Digital Performer.

While playing back a MIDI file in Digital Performer to the Montage, the file playback halts briefly every time I change sounds on the Montage.

This happens when using either the Montage's USB port or dedicated MIDI ports/cables.

This happens when running the Montage in 16-part 'multi/GM' mode, with only a single track playing, and changing the sound on a different track.

Has anyone else noticed this?

Thanks.

The question should be, “How can I avoid this?” The fact that you are experiencing it is quite enough, I’m sure, to just go ahead and ask how to avoid this.

It would be impossible not to notice a song file halting during playback, so the thing would be to try to avoid this entirely.

Are you using MONTAGE CONNECT running inside Digital Performer?
MONTAGE CONNECT is a utility plug-in (VST/AU) that will capture, store and restore your MONTAGE PERFORMANCE and keep that data with your DP data. Each time you open the project file, MONTAGE CONNECT can automatically restore your Performance to the MONTAGE.

This will avoid having to store and having to manually recall the Performance on the MONTAGE hardware when you want to play the song file. The MONTAGE CONNECT will bulk the Performance to the MONTAGE even before you hit Play. Everything stored bundled in your DP File.

Next, you need to know that sending certain Bank Select (MSB/LSB) and Program Change (PC) combinations will recall all 16 Parts as a set (Multi).
Other Bank Select and Program Change combinations will change a Single Part on a single channel. It is this second type, that you want to use.

You will not, in all likelihood ever be able to use the former during a Song (you can’t have the Duke Ellington Big Band, swap seats with the Count Basie Orchestra within a 64th note; but you can switch the sax to a flute in blink of an eye.*
* rather rapidly.

If you are attempting to swap all 16 seats (you’re dreaming) that is not going to happen and remain sonically invisible, if you are attempting to change individual instruments on an individual track, that is completely possible... I can provide you with demo files that easily switch several instrument during playback. It’s the standard General MIDI-type workflow, where you are selecting/changing instrument sounds during the song on specific channels.

Do’s and Don’ts:
You cannot place a Bank Select / Program Change on the downbeat along with notes that are to be played. Logically. MIDI is serial, one event after the other. The Bank Select should precede the Program Change, the Program Change should precede the musical notes... it’s stupid simple logic... if you send notes first, they’ll play the previous instrument, if you send the PC before the BANK, what if the Bank has no such program number? (not all banks have the same number of Programs). So switch the Bank, then select the instrument Program, then play the notes. Logical.

If the notes are to be played on the downbeat, then place your Bank Select/Program Change events slightly before the downbeat. It’s the same place recording engineers learn to “punch in”... here’s what I mean, when you need to surgically need to begin a punch in recording, the engineer looks for the slice of time when the musician is “drawing a breath”... it is that exact moment of silence, before the sound; that small slice of time when the singer is breathing in before attacking a word, that moment when the keyboard player’s hand is just starting on the way down, etc. the punch in spot is within that moment where it will not be detected; you want to place the change events precisely so that they remain sonically invisible.

A few clock ticks BEFORE the downbeat. You cannot change programs during held notes, obviously. Therefore move your change events BEFORE the Note events... how far? Far enough so they do not disturb the sound you're changing from, and do not disturb the sound you’re changing to...

At 480 clock ticks a quarter note, for example, a 64th note is 30 ticks...which is way more than you’ll ever need to make a change between single instrument sound, in general... tempo does makes a difference, naturally, but you’re a musician, changing instruments is supposed to be sonically invisible. Once you know how this works, it is very much your responsibility to place these events where they belong. If you hear a hesitation move the events causing it... leave the notes where they belong.

Just FYI ...
SINGLE instruments have MSB 63/ ... used to recall individual instruments on individual channels
MULTI Performances have MSB 64/ ... used to recall entire multiple Part Performance
Live Set (Multi Performance) have MSB 62/ ... not for use with sequencers

Recalling Normal PARTS (whether AWM2 or FM-X) are quick to recall, 8 oscillators max
Recalling Drum Kit Parts (AWM2) are necessarily slower, 73 oscillators

And final word, if your change is not sonically invisible, find a different solution. Music is such that not all instruments are in (playing) all the time... find an easier place to put the instrument you are changing to. Don’t let you eyes decide what works, Music is always about the ears.

I say that because for your eyes you will likely place two quarter note chords, occurring beat 1 and beat 2, each held all 480 clocks... your eyes will make that look neat on the piano roll...
But you can’t play that ... you cannot lift and retrigger a chord within a single clock pulse. You cannot. You’re human. And you don’t have to! You’re human!
Good enough for your ears, is actually a lot of clock pulses between one chord ending and the next one beginning... the space (time) between the first chord ending and second chord being struck... that’s something to consider when you consider placing your events. (I didn’t mention Sustain pedal but obviously that is the same as changing *during* the sound).

I think it is important for musicians to learn about “time” as it relates to sequencers. What qualifies as a whole note... in theory at 480 ppqn would be 1,920 pulses per measure... how long do you actually hold it?

Thanks BadMister, great info!