[LAD] audio/midi app development

Hi, Is it common experience when (design/code/test module repeat) a real time audio or (as in my case) MIDI application, that, as soon as you finally solve a problem that's been bugging you for ages, and take a step forward, you immediately step upon another whopping great pile of @#$!??? It's taken me at least four months so far to get as far as I have with my app. There is still not a single MIDI message emitted from it yet. It has a GTK GUI with almost as much as 0.01% of the features the GUI will eventually require. I've been pretty obsessed with it, spending a high percentage of my spare time attempting to code this. Incidentally, if I want the GUI to update very close to real time, say a grid of blocks flashing on and off as notes come and go, any thoughts? Would a GTK GUI update fast enough? I'm also wondering about going for an "Immediate Mode" GUI using SDL, possibly with OpenGL, I'm unsure... It's a way off yet, I'm concentrating on getting the engine working without a UI first. Cheers, James.