This is a question related to the rendering of midi signals. At times BiaB yields strange results when playing back its arrangements. Usually midi notes do sound during their midi duration. However, at times they do sound substantially longer. Why?

Here is how to reproduce this finding:
Load the demo song of Jazquint.sty. Set Guitar to solo such that you hear exclusively the guitar track; potentially reduce the tempo to s.th. like 60. Turn the chord Dm7 in the second bar to a shot. Press play and focus on the guitar notes of the Dm7 shot. Various synthies now yield different results. VSC DXi makes the guitar notes sound exactly during their midi duration here. Forte DXi and GS Wavetable, however, make these notes sound substantially longer - effectively botching a shot effect.

Now comes a related question.

With the style Jazquint.sty a typical guitar pattern are strums at each beat. Typically these strums are notated with respect to the respective midi durations -> long-short-long-short (long refers to durations of about 0:100, short is typically s.th. around 0:20). At times, though, some bars show up with midi durations short-short-short-short. At those bars the synthies create the following puzzling patterns -> Forte DXi: mostly long-short-long-short and sometimes even long-long-long-long, VSC DXi: long-short-long-short, Wavetable: long-short-long-short.

Why do different synthies create different renderings with respect to note durations?

Why do some synthies create long-short sounds with notes of durations short-short?

Dare I guess reverb in the samples?

Oh well, some inspection with the midi monitor reveals that there are a bunch of sustain controllers floating around with the midi data created by this style. Those song positions that create long sounding notes even if the note durations are rather short are accompanied by some non zero sustain controller values. Typically these values are indeed 127. That seems to account for long sounding notes with short midi durations.

Now, why do different synthies create different outputs?

In the second bar with the shot, the notes start out with a sustain controller value 127. At the end of the note durations the sustain controller value is turned to 5, not to zero.

Apparently different synthies react differently to sustain controller values, such a 0 correnponding to 'off' and any value different from 0 may correspond to 'on'. The VSC DXi seemingly takes a value 5 just as this value, thus effectively switching off sustain.

That is an interesting problem that popped up recently over at the German forum ...

Yes, different devices do indeed respond differently to MIDI controller 64 (sustain).

The 5 is not generally a problem, though, as the vast majority of GM synths use the 0-127 CC as a "bang-bang" and not a continuous action, typically defining the dividing point between Pedal Up and Pedal Downs at the halfway mark, or 064. (Here's where guys like Gary will chime in about their special Sustain Pedal situation, which is programmed to emulate half-damper action. You can get it, but it is going to cost you more money, whether hardware like Gary's piano or software as in some of the high end piano modeling synths. )

So the 127 is a Pedal Down and the 5 represents a Pedal Up. This is a common MIDI programming practice when creating a MIDI file for use with different GM synths because there exist some synths that don't like going all the way to zero, can't recognize it ("1-based" synths, for example). So setting the Controller for a number slightly above zero makes sure that every possible situation can be handled with the same setting, "5" or "3" being the same action as zero anyway.

The situation can be further exacerbated by certain software synths and their implementation, too. It is customary if not de rigeur to not send MIDI Note Off data in a MIDI file. Even though the original MIDI standard includes Note Off commands, it was found early on that the inclusion of the Note Off commands was superfluous for the most part, bloating the size of MIDI files needlessly when the MIDI Note Duration command literally does the same thing as a Note Off command placed at the end of every single note in a file. But there are indeed certain times when certain softsynths, particularly those of the DXi persuasion, will miss the Note Duration data point, causing longer or shorter notes, often causing the "hung note" situation, particularly on Pad tracks such as strings, synths or organs. That bug has been reported here numerous times. I have never found a cure for the situation other than to switch to a good hardware MIDI synth, where none of this has ever occurred here.

As for CC64 being used on guitar parts, I try to avoid that situation in my own MIDI sequences, simply because the real guitar has no sustain pedal in the first place. That is really something only the Piano, and a few other percussion instruments have in real life. Harp, etc. Still, even given that, the use of the Sustain CC64 is with us forever more than likely, especially in those downloaded-for-free MIDI files that are so ubiquitous. The funny thing about that situation and human nature is that almost everybody will blame the host program they use or the developers of the host -- and never the free downloaded MIDI file from an unknown stranger that they are trying to get to act right.


--Mac

I read you Mac, yet here we have a pure BiaB setting - not talking about some downloaded midi files; it's all about the midi data created by BiaB.

The CC#64 controller value was probably a misleading trace anyway. Shifting the guitar track to the melody and editing the suspicious sustain controller value 5 down to 0 does not change anything with the strange playback behavior. Now what?

Maybe some soul from PG Music might chime in here ...

Quote:

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The situation can be further exacerbated by certain software synths and their implementation, too. It is customary if not de rigeur to not send MIDI Note Off data in a MIDI file. Even though the original MIDI standard includes Note Off commands, it was found early on that the inclusion of the Note Off commands was superfluous for the most part, bloating the size of MIDI files needlessly when the MIDI Note Duration command literally does the same thing as a Note Off command placed at the end of every single note in a file.

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Mac,

I've never heard of a "MIDI Note Duration" command..
Can you please explain in more detail? How is it defined in the MIDI standard?

Thanks.