[beckerdo]

"Physical UIs also don't need to help the user navigate digital content. Hugely different to physical content."

Consider the Beat Buddy pedal (automated drum accompaniment pedal) which can play lots of digital content via user commands. Yes the foot commands are limited ("add a fill", "splash sound", "next phrase", "end song"), and so are the dials ("choose playlist", "change tempo"). However, the proper stomping really helps if you want to add an extra solo or just chill with a beat while you tell a story.