As a musician who plays multiple instruments, I've been thinking of doing a video in which I, alone, plays the "whole band". This would be acheived by me recording myself playing each individual instruments, then putting it all together in a video software. There would be 4 or 6 frames of videos going on simultaneously with the sounds together as well...
Recently, I saw this video on google:
and that's pretty much like what I want to do (but with less arms-flailing and more actual-instruments/music :P )
So, what software should I be looking to invest into?