Playing a MIDI keyboard without JACK / how to use JACK and PulseAudio/ALSA

Question

So, I havea MIDI keyboard but I'm not really motivated to play when I have to set up JACK and everything else just to get one sound out of it. The problem is that whenever I start JACK I can't play sounds from YouTube, Move Player, RhythmBox, etc. because JACK is taking over the soundcard.

Here's how I start JACK and my MIDI keyboard:

$ pulseaudio --kill
$ jackd & qjackctl & amsynth

(plug in keyboard)

So, apparently JACK needs the PulseAudio soundcard. But here's how I exit JACK:

$ alsa force-reload

I've tried pulseaudio --start but this seems to be the only thing that works. So I'm not really sure whether it's pulseaudio or alsa that I need to play rhythmbox/youtube/etc.

So, my question is: Is there any way I can play my MIDI keyboard either without JACK or finding a way I can use JACK and still play RhythmBox etc.? Or maybe a non-JACK MIDI controller? I've tried

$ jackd -d alsa

and that doesn't really do anything...I still can't hear non-JACK audio...I don't really know what that's supposed to do either, I admit.

I'm using Ubuntu 12.10 on an Acer AO722 with an Alesis QX49.

Answer 1

To let Jack and PulseAudio work together better, you should use pasuspender.

With the options -m alsa -a alsa, amsynth should not use Jack. (You can the use aconnect to connect the keyboard to the synth.)

Answer 2

This is all entirely untested because we do not have a MIDI keyboard here. Nevertheless let me give you some good resources from where you may be able to get MIDI and other audio play together in harmony.

When running JACK you have several options on what to do with PulseAudio, as outlined in the JACK Wiki (commented by me):

• Do not use JACK and PulseAudio together
  this of course lets you control your sound system entirely with Jack but you may run into trouble with applications that rely on the presence of Pulseaudio. After removing PulseAudio to replace it with JACK it may not be easy to reinstall Pulseaudio again in case we realize we do still need it.
• Use two different sound cards
  this means you have one soundcard for PulseAudio and another card for JACK. Not easy to set up without quirks, and involves buying new hardware.
• Route PulseAudio to JACK while JACK is running
  this may be an elegant way to have both sound servers running in harmony. See also the PulseAudio Wiki on how to set up the PulseAudio JACK modules.
• Suspend PulseAudio while JACK is running
  by making sure to suspend Pulseaudio (as it is already answered) whenever an application uses JACK we may be able to run applications for both PulseAudio, and JACK, but never at the same time.

You may also find answers to the following question helpful:

• Step-by-step to run a midi keyboard input device? 12.04

  Have a look at rafalcieslak's rather underrated answer there, where he also gives you a link to his nice blog on that topic.

Answer 3

If you choose to use jack , which is a rational assumption for audio/midi capturing and playback, you can play sounds from your keyboard and still route the default audio device to jack so that youtube and other application continue to work.

See the chosen answer here.