In 18th-century Europe, the 'musical dice game' (Musikalisches Würfelspiel) was a fad: roll dice to chain written bars into procedurally generatedmusic. 'KV 516f', attributed to Mozart, can produce about 1.3×10^29 pieces.
Piano keys were originally reversed from todays layout. In the era of Mozart and Beethoven, the wide keys were black and the narrow keys were white. This was likely because ivory, used for white keys, was more expensive than ebony used for black keys.