Having spent an evening trying to get Linuxband to talk to Qsynth using many hit-and-trial methods, decided to do it the hard way, i.e. by understanding the Linux MIDI workings a bit better. Especially, one of those things that confuses people are the abstraction layers, sound managers and how they interact -- especially given that there are multiple alternative ways of achieving the end goal of getting some sound out (or in), but with some side-effects (or not). How JACK, ALSA, PulseAudio, OSS interact, for what all, why is somewhat of a deep rabbit-hole that can take you to Wonderland or Oz or Narnia.
Two things which are really handy are: