Piano rolls, the backstory (as I believe hip young people in Hollywood put it).
Once upon a time someone invented an instrument that was big, heavy and square. In it were strings that were hit by hammers, and you made the hammers work by pressing down white and black keys. This was called a "pianoforte", or "piano" for short, meaning "soft and loud" because unlike the organ or harpsichord you could play it softly or loudly just by how you pressed the keys.
The instrument became very popular and over time became a fashionable household item and a standard fixture in pubs, saloons and other places of low entertainment.
Unfortunately it took not just some talent but also a lot of practice to become proficient at playing the piano. Which is hard work. But people wanted to hear music and records hadn't been invented yet. What to do?
The answer was a self-playing piano, or "player-piano". Which, if the link to an off-site image works, looks like this
http://coachingcounsel.co...13/06/playerpiano1.jpgWhich it doesn't because on iOS most of the editing tools for the forum are missing. Never mind, just click on the link.
Now, please note the roll of paper located centrally above the keyboard. That is a "piano roll". It is several feet of rolled up paper in which are punched lots of holes. To make it work the piano roll is wound past a mechanism which detects the holes and makes the piano play the notes.
And the view in DAWs called "piano roll view" is a virtual version of the same thing, only far more powerful and not operated by clockwork or the user having to crank a handle, or like the one in the picture, work pedals at exactly the right speed.