Poor Monome, with just 64 buttons. Back in the 90s, Nicholas Fournel (who just sent us his MIDI tablet software) built a massive plexiglass touch-screen instrument called the Semekrys. Two of them were sensitive to a 1000×1000 grid. (Okay, not quite the same as 64 buttons, but then this is transparent and looks absurdly cool even in an age with more touchscreens.)

Proof that the search for expressive touch interfaces is still an ongoing one: