Record what you play, with timing, by default #16
Description
Including playing back tabs, because you can make interesting new things by pressing multiple notes at once and making new rhythms; you could alternate between pressing 2 and 3 or 4 different keys at once, etc.
"So much of art, so much of creation is discovery" -Bret Victor, Inventing on Principle at ~5:24
And it's easy to discover interesting new things with this. I want to make capturing those discoveries easy, frictionless, effortless, literally not something you have to think about. You can't know when you're about to do something creatively interesting, when you're about to improvise something new and fun, or just make an accidental variation on a melody, before you do it, you can only recognize it afterwards; so it makes sense--that is, it follows that our tools should support recording retroactively.
(I call it "precording"; you could also call it "retrocording")