A study hint from a bunch of octopi Published December 6, 2012 at 400 × 350 in READ MY LIBRARY ENTRY 47: Finally! The End of The Aquaman Archives Volume 1! Here Aqualad gets the answer to “How many keys on a piano?” from Octopi waving their tentacles wildly. Because 16 waving tentacles is the best cue to make one think about piano keys!