This is LSDj running in a special version of VisualBoyAdvance that allows Lua scripts to be executed. This script that I wrote does two things:
1) It shows the currently active waveform in channel 3. You'll understand why in a few days.
2) It shows the currently played note on the three note channels, with a piano roll and a number for the octave.
As someone said to me "may i say this is as useless as attractive? 
". Thought I'd share.
Edit: I apologize for the crappy sound quality and low volume.
