Credit for the graphics goes to FFR user Scylaax. 

Comparing the music spikes of the original Mario music to the drum sounds superimposed, obviously the drums are going to take priority regarding sync accuracy because their hits are sharp appose to distorted waves produced by Super Mario 3. All drum steps are accurate within five milliseconds (and, again, the Mario track generally coincides). However when the gap did grow too big, I placed them separately.   