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qtractor pitch bend

HI, I'm trying to migrate to linux for preparing a show and performing live. It's been a time consuming process going through all the daw's to find out if they are suitable. Right now I'm working with qtractor which I was starting to think would work out until this hiccup. Qtractor is ignoring pitch bends in midi tracks. I have no idea how to fix this or why it is happening. I've tested other software under linux with the same midi file and the same plugin, and it works. I was really hoping qtractor would work out because it is possible to save complete track setting from one project to another giving my backup "band" consistency from song to song. Please help!!! thank, Robb

PS using qtractor 0.9.114 appimage on mint that is setup for audio.

rncbc's picture

whatever you were using, i guess the root cause for your problems might be in that precise end of the plot then.
just a thought. definitely not a qtractor issue, i say.


btw, this midi file when played on ableton live, the guitar has a pitch bend range of 12 semitones.....nothing subtle about it.

rncbc's picture

again, that is a setting on the MIDI instrument end, possibly named "pitch-bend range" or "sensitivity", for which qtractor has no direct access or control (it depends on its MIDI implementation).

please refer to the SF2 sampler instrument you're using or try with another one... here tested with qsynth (standalone), fluidsynth-dssi, calf-fluidsynth (plugins), linuxsampler (server) and through a DB50XG outboard (full old XG, non-SF2 based) -- all played well re. MIDI pitch-bends (although the later with better sound quality ;)


I just want to make sure that we are clear on something. You're telling me that qtractor is a sequencer / midi editor / plug-in host that will not enable you to send the proper midi message to change pitch Bend sensitivity.?? Is this what you're telling me?

rncbc's picture

no. i'm saying that it depends on the MIDI instrument or plugin that is being driven by.

although, there are some MIDI (N)RPN in the known standards (GM, GS, XG) that comes to mind, which makes up for pitch-bend sensitivity or range (usually in semitones or cents for full-swing or scale) to be set on-demand, a possibility that only gets effective if , and only if, both of the following conditions are met:

1) those pitch-bend range/sens. instructions or messages must be part of the MIDI file being played or sequenced: qtractor will duly pass them on to the instrument, but...

2) the instrument (or plugin) must recognize and react to those messages and set its own pitch-bend scaling factors to fit the desired range or sensitivity upon rendering the normal MIDI performance pitch-bend messages: which as I've demonstrated, are being handed out properly by qtractor, as long there are any in the MIDI sequence, of course.


WAIT! I think I see the problem now: the file "Eagles_(The)_-_Hotel_California.mid" seems to be formed under the MPE (MIDI Polyphonic Expression) specification... alas, qtractor doesn't support the MPE spec. in fact, in qtractor terms and convention for MIDI sequencing, the file is just malformed and thus it wouldn't ever play it right, no matter which instrument or plugin you throw at it, even though the instrument have to support and accept switching into said MPE mode too. sorry :)

so, after all we were both misguided after all this time. it wasn't ever about pitch-bend or not: it was all about MPE instead, that I repeat, qtractor does not conform or accepts.

to my knowledge, there are none of open-source applications (on GNU/Linux at least) that support MPE to date. there are some, non-free, commercial ones that might (bitwig, reaper, and so on...). same for instruments, plugins, unfortunately, whatever.

anyway, I don't know how far and that said support goes on other commercial software, but one thing I'm sure: qtractor doesn't, sorry again; only conventional MIDI files and sequencing do work, which boils down to one rule: one track, one channel, one instrument, one patch.

apologies for all the fuss :)

Hi thanks for the info....just one final can one identify a midi file that is the wrong type.....or the right type? thanks

rncbc's picture

they are perfectly legal SMF (standard MIDI files), only that they include special MPE mode setup and performance events, which are special MIDI (N)RPN events that in turn are normal MIDI CC events, just with designated special values, according to the MPE spec.

so, you'll have to read and decode the MIDI file and look for those special magic events that often occur at the head of the first MTrk section, usually for MPE Configuration Message (MCM), which is plain MIDI RPN 00 06.


Agreed. You might want to also test with Carla since I believe that loads soundfonts.


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