Make timidity use dmix
It annoyed me for quite some time now that playback in TuxGuitar only worked when I closed all other audio applications. The reason for this was that timidity, the midi software synthesizer I use didn't use the software mixing (dmix) provided by alsa. The solution to this is quite simple. Edit /etc/default/timidity and replace this line:
with this one:
TIM_ALSASEQPARAMS="-Os -o default"
and then restart timidity:
You should now be able to use TuxGuitar and every other application that uses midi together with other audio applications