The downside to an MP3 culture is that its pretty solitary. If I want to make a mix for the wife, I have to buy an .mp3 player and just give it to her - or I have to go retro and burn a CD. It's better than the 1990s, when people made cassette mix tapes - but they certainly showed you care. It was no trivial thing. You can bet if I told my wife today I made a mix tape for another woman, she would be going to get her pistol.
Makerbot has brought them back - but with a modern twist.
You can make it in your house on a 3-D printer. But it won't work in a cassette player, it is still basically a USB drive.