Regarding how music is distributed to consumers:
- My first record player had no electronics (the tonearm had a kazoo like diaphram that vibrated from the needle movements). No volume control, but there were two sets of "needles", soft and loud. It played 78 rpm records, which was most of the records I had, but it also played 16 rpm "story" records.
- Later, I had a record player with a built in amp and a bunch of 45rpm records.
- 45s gave way to 33rpm lps (albums) which lasted through high school and most of college. I had thousands.
- We recorded our friends' albums on cassettes, which never sounded as good as the records.
- Along the way, many people collected 8 tracks, a format I never persued.
- CDs appeared when I was in college, and many of us slowly replaced our vinyl with that format.
- Various other formats came and went without much success: the EL Cassette, DAT, Minidisc. DCC, Laserdisc, VHS HiFi (which was very successful as a video format, but despite being superior to cassette and about the same price never really caught on for music), Sony F1 digital, DMX radio over cable, etc.
- mp3s were next, despite sounding like dogmeat at low bit rates, but the dominant distribution format for a while.
- Today, streaming is the thing, with a significant pushback for either physical media or data files you actually own.
Six decades, dozens of distribution formats, the dominant ones only lasting a decade or so. Which is to say that the current way of distributing music (streaming) will probably be replaced with something else. What's next? No idea, but the current situation is not sustainable.
I was about to say "streaming's days are numbered" but the dinosaur AM radio stations still walk the earth, so it's obituary is premature.