Where did the piano notes/keys originate?
Well, the history of “notes” in general goes back further than we could possibly discuss. After all, the first unpitched percussion, the warblings of songbirds, etc., all produce notes of some distinct pitch, although combinations of these pitches may not necessarily sound like music as we know it. Maybe what you’re really interested in is how “music” in general became the specific chromatic (that’s that sequence of alternation of black and white keys on the keyboard) scale that we use today. Diatonic “scales” go back further than the recorded history of music, but there was little use of those in-between notes, the chromatic non-diatonic pitches, until the flowering of the Renaissance, somewhere around the 1400’s. There was “organum” which had happenstance chromaticism because of the specific way the notes moved, but no real use of all “12 keys” that we have now. Around the time of the Baroque (1600-1750), composers began to start using more colorful “chromaticisms”, using these notes
