What are piano rolls?

Question:Before they had electricity or computers, Artisans devised a way to record performances and even create what seemed to be impossible combinations of keys by means of a roll of parchment paper with square holes punched into it. The first computers used a very similar "punchcard" method. When the hole is punched, the air pressure escapes and the hammer hits the string. When the hole is plugged up again, the hammer swings back and gets ready to hit the key again. The whole system is powered by air pressure, or pneumatics, and was originally pumped up by a set of foot pedals that swung out from the body of the instrument. There is a similar digital system used by Yamaha and Kawaii these days, but it is recorded on a cassette tape or a disk. The Aeolian Piano Company was the predominant maker of player pianos and piano rolls. Hope this helps.

Best Answer - Chosen by Asker: Before they had electricity or computers, Artisans devised a way to record performances and even create what seemed to be impossible combinations of keys by means of a roll of parchment paper with square holes punched into it. The first computers used a very similar "punchcard" method. When the hole is punched, the air pressure escapes and the hammer hits the string. When the hole is plugged up again, the hammer swings back and gets ready to hit the key again. The whole system is powered by air pressure, or pneumatics, and was originally pumped up by a set of foot pedals that swung out from the body of the instrument. There is a similar digital system used by Yamaha and Kawaii these days, but it is recorded on a cassette tape or a disk. The Aeolian Piano Company was the predominant maker of player pianos and piano rolls. Hope this helps.

in the old days there were pianos that used rolls that had the music on them and played themselves. They are kind of on the same principal as a music box but the rolls were cylindercal
You can probably find a picture -----just google it