Maybe the cartridges could even contain the actual music. On an engraving that stores the audio information perhaps. This engraving could be played back and reproduce the audio. It probably would never work though.
“The actual music” is just so hard to contain. A recording of a performance - is that the actual music? Or is the actual music the playing back of the recording with speakers and audio? Will all that be in the box? Or is it the entire band in your proposed box, ready to play whenever you pull it from the shelf? Or is it what you hear in your head in the shower?
Hmm, I’m thinking that for this to work best, it really should be some sort of round medium, a disk or a cylinder of some sort. I think disks might be best because then you could engrave the music on both sides of the disk and more easily store them in protective containers on shelving units.
Sounds like it’ll be quite the innovation.