[solved] Qtractor: start/stop Drum machine?

[Linuxmusician01]

Maybe @rncbc (Qtractor's developer) will answer this question. As mentioned in the manual:

If a synthesizer has a built-in sequencer, then the only MIDI signals that need to be sent to that device are START and STOP. This is common in external drum machines, which inherently manage their own sequencing so that you can create drumbeats and loops on them using a fairly familiar interface (familiar as long as you’ve used drum machines, anyway).

How do i do that? I've managed to let Qtractor play a Midi sequence on my drum computer (Behringer RD-6) via the Midi cable connection between it and Qtractor. But I can't seem to manage to simply use the sequence I've programmed in the drumcomputer itself... When I add another track to Qtractor and play that one then I see the "Start" button on the drum light up. But it's waiting for Midi-note info that it doesn't receive...

[rncbc]

hi, kinda lost without further details.

but still, the start/stop "signals" mentioned in the manual are the ones related to MIDI 1.0 SPP messages (for Song Position Pointer; cf. View > Options... > MIDI > Control > SPP = Output|Duplex); and, ofc. these are out through the Control output port if you chose to have dedicated or the first MIDI output bus, eg. Master Out, if not.

[Linuxmusician01]

hi, kinda lost without further details.

but still, the start/stop "signals" mentioned in the manual are the ones related to MIDI 1.0 SPP messages (for Song Position Pointer; cf. View > Options... > MIDI > Control > SPP = Output|Duplex); and, ofc. these are out through the Control output port if you chose to have dedicated or the first MIDI output bus, eg. Master Out, if not.

Thanks for your reply. What details would you like to know? The SPP is indeed set to Duplex. But when I start playback in Qtractor my drumcomputer does not start playing its own sequence (i.e. the one that I programmed in the drum-computer itself). That is: I'd like to send the drumcomp. a Midi Start signal.

In Qtractors 'Connections' window I've connected the drumcomputer's Midi IN to Qtractor's Midi OUT. I've set the drumc. to accept it's tempo ect. via Midi and I can start and stop the drumcomp with the command line program sendmidi. But Qtractor won't start the drumcomp. How do I do that...?

[rncbc]

if the MIDI/Control/SSP option is set to Output or Duplex then you should get:

1. MIDI Start message when playback starts;
2. MIDI Stop when it stops;
3. MIDI Song Position Pointer (SPP) when you change the play-head ad-hoc.
   as mentioned, these messages are sent either through the dedicated MIDI Qtractor:Control output port OR the Qtractor:Master Out bus port (if opted to have no dedicated MIDI Control ports).

check with eg. aseqdump on either of these output ports wheter you see those events being transmitted.

ps. however, if you're also connecting the said drumcomp to Qtractor MIDI Master/Control Inputs then, due to the "Duplex" setting above, you're also set for a deadlock/loop race, as qtractor will also respond to those MIDI SPP messages if the dang thing is also sending those same MIDI SPP messages when started or stopped.

[Linuxmusician01]

These are the outputs of aseqdump commands:

Code: Select all

$ aseqdump -l
 Port    Client name                      Port name
  0:0    System                           Timer
  0:1    System                           Announce
 14:0    Midi Through                     Midi Through Port-0
 16:0    C-Media CMI8738                  C-Media CMI8738 MIDI
 24:0    SINCO                            SINCO MIDI 1
129:0    Qtractor                         Master
129:1    Qtractor                         Player

The drumcomputer is the Sinco Midi device. Are ports 129:0 and :1 the "Qtractor:Control output port OR the Qtractor:Master Out bus port"?

The port 129:1 (Qtractor Midi Player) does not output data. The other indeed outputs the Start and Stop messages when I press play in Qtractor:

Code: Select all

$ aseqdump -p 129:0
Waiting for data. Press Ctrl+C to end.
Source  Event                  Ch  Data
129:0   System exclusive           F0 7F 7F 06 44 06 01 00 00 01 07 00 F7
129:0   Song position pointer      value 10
129:0   System exclusive           F0 7F 7F 06 44 06 01 00 00 00 00 00 F7
129:0   Song position pointer      value 0
129:0   System exclusive           F0 7F 7F 06 02 F7
129:0   Start
129:0   Note on                 1, note 36, velocity 64
129:0   Note off                1, note 36, velocity 0
129:0   Note on                 1, note 40, velocity 64
129:0   Note off                1, note 40, velocity 0
129:0   Note on                 1, note 36, velocity 64
129:0   Note off                1, note 36, velocity 0
129:0   Note on                 1, note 40, velocity 64
129:0   Note off                1, note 40, velocity 0
129:0   Control change          0, controller 120, value 0
129:0   Control change          0, controller 123, value 0
129:0   Control change          1, controller 120, value 0
129:0   Control change          1, controller 123, value 0
129:0   System exclusive           F0 7F 7F 06 01 F7
129:0   Stop
129:0   System exclusive           F0 7F 7F 06 44 06 01 00 00 00 1A 00 F7
129:0   Song position pointer      value 7

Screenshot of the Connections window:

The light on the drumcomputer's Start/stop button lights but it does not start to play... It is connected to Midi Channel 1 because it makes sounds if I send midi data to that channel. I've made 2 Midi tracks in Qtractor: one on Midi Chanel 1 (empty, no clip, no Midi data)) and one on Channel 2 (w/ some data/notes in a Clip) because if I don't then Qtractor won't play.

[rncbc]

the MIDI Start/Stop/SPP events are NOT MIDI channel messages: they apply to the system they are sent/received as a whole.

so it's down to your target device; you already notice the start/stop buttons get lit so the messages are being received alright but no reacted upon... so, I suppose qtractor is off the hook then... check your device manual, maybe it needs something else? like MIDI Clock?

[Linuxmusician01]

the MIDI Start/Stop/SPP events are NOT MIDI channel messages: they apply to the system they are sent/received as a whole.

so it's down to your target device; you already notice the start/stop buttons get lit so the messages are being received alright but no reacted upon... so, I suppose qtractor is off the hook then... check your device manual, maybe it needs something else? like MIDI Clock?

You're right! The command line utility that I use to start the drum computer also doesn't work anymore if I delete the clock part. How do I send clock data via Qtractor?

[rncbc]

How do I send clock data via Qtractor?

Options... > MIDI > Control > MIDI Clock = "Output", obviously

[Linuxmusician01]

How do I send clock data via Qtractor?

Options... > MIDI > Control > MIDI Clock = "Output", obviously

Obviously! Works like a charm. I thought that it was set in the menu bar via "Transport > Mode > none/slave/master/full" Thanks for the help. I learned something more about Midi today.

There are such a lot of settings in a DAW. Pfew.