QWERTY piano
Your computer keyboard as a piano, the way Ableton lays it out. The home row plays the white keys; the row above plays the black keys between them, sitting where they sit on a real piano. No mouse aim: your fingers rest on a whole octave at once.
Play
Click the pad to arm it, then type. A to L are the white keys from C; W E, T Y U and O P are the black keys wedged between them. Z and X move everything an octave; C and V make the next notes softer or louder. Keys match by position, so non-QWERTY boards work too.
Why this layout
It mirrors the piano: two rows of letters shaped like the two rows of keys. The gaps in the top row (R and I stay silent) are the same gaps a piano has, where E meets F and B meets C with no black key between. Notes here are one tap, one sound: no holding for sustain.