pulseaudio

restart

Check if any pulseaudio instance is running:

pulseaudio --check

It normally prints no output, just exit code. 0 means running. Mine were not running, so I just advanced to step 3.

If any instance is running:

pulseaudio -k

Finally, start pulseaudio again as a daemon:

pulseaudio -D

Start banshee again and enjoy!