Other people also asked about potential support for shorter and longer tunes. I’m tempted to add this at some point, but that would also make compression more tricky.
If only the Playdate had a built-in camera. Then it could simply scan a QR code or something. I have a feeling that the SDK will sooner or later have networking capabilities (e.g. for exchanging high scores), so at that point the doors will probably open up for some online tune exchange system.