In this video by Brick Technology, they make a LEGO drum machine. It works a bit like a music box, with a set of eleven piezoelectric drum pickups each actuated by its own Technic-built drum stick. These sticks are labeled, in order,
and I can't for the life of me figure out what all the letters means.
I'm familiar enough with drums (and can hear well enough to figure out) that K is for the Kick (or bass) drum, S is for the Snare drum and H is for the Hi-hat. Some investigation into the matter indicates the the three T's are most likely for the three Toms, with the two C's for the Crash cymbals and the R for the Ride cymbal, but I am not as confident with this assessment. And I can find nothing to determine what the two A's are for - are they just "Auxiliary" percussion, or is there some part of the kit that starts with A?