MIDI play along and .flac .m4a slowdown.

[globetrotterdk]

I have a laptop with Ubuntu Studio 14.04 installed. I have just started taking piano lessons to extend my knowledge about music (I otherwise play saxophone). I have found out how to get my keyboard (M-Audio Keystation 88 MkII) working with QjackCtl and Qsynth. My piano teacher has started sending me some .m4a files (I personally prefer .flac) by SMS to my iPhone, that I save to Dropbox. I need to play these files from my laptop at the same time as my keyboard is also sending MIDI signals to my computer. Optimally, both need to be sent to some Bluetooth speakers that I have in my rehearsal room. It would also be excellent if the .m4a could be played by a slowdown program, so that I can more easily play at my own tempo.

While not a complete Linux newbie, I am in the area of audio and MIDI devices. I assume that the easiest way is to continue to use QjackCtl and Qsynth. Continuing on that trail of thought, I assume that I need a slowdown program that can be piped through QjackCtl at the same time that Qsynth is being used to pipe MIDI signals. Is this correct? Can this be done? What program do I need (I am aware of a few possibles, Audacity, Amazing Slow Downer)? Do I do this through QjackCtl? Thanks in advance.

[bluebell]

An m4a-file contains audio, not MIDI.

You can convert them to wav with
mplayer -vo null -vc dummy -af resample=44100 -ao pcm:waveheader:file=audiofile.wav audiofile.m4a

Qtractor is a sequencer that slows down audiofiles automagically when you change tempo. Import the file into Qtractor, drag it into a newly created audio track and play it.

There are probably 1000 other ways to slow down an audio file.

[globetrotterdk]

Thanks for the information. Is it possible to play audio and MIDI at the same time, with speaker output? The "play along" aspect is important.

[bluebell]

Yes. Playing along is no problem.

It's important that your system is well tuned. If you use JACK (and you should) then make sure to use the smallest working value for the period size (-p parm, Periods/Buffers in qjackctl) to have low latencies.

[globetrotterdk]

Seems to be working fine. Many thanks.