a song i composed is being sent to the moon on an SD card or flash drive of some sort, i was told. Realistically if there is some faster-than-light mechanism, any interested alien or human could just "fast forward" and "rewind" through time to listen/watch our broadcasts from the appropriate distance from the original location.

Barring that, I'm guessing the equivalent of stone tablets, or the golden record are the best bet. I wouldn't place any bets on anything that requires magnetism or electricity to survive in open space for long enough to matter. Like, platter bit-flips due to radiation from outer space are a thing, and current leakage would eventually render something like SSDs unreadable.

So hard copy for earth, radio and hard copy for the universe?