A friend showed me a cassette tape that he found.

"Look at this!" he said as he pushed the play button. Music, obviously recorded off the radio, came out of the boom box. A symbol of an era long gone.

We listened for a bit. There was some Linkin Park. Some Green Day. Some garbled bits. We got to the end, the tape stopped, and then automatically started rewinding. We listened quietly to the whirr of the machine.

"...What do we do now?"

Before cassette tapes, you either bought vinyl records or listened to the radio. But a medium for both playback and recording was revolutionary. Recording tunes off the airwaves was trivial, if not a bit janky - you'd probably catch a bit of the DJ or a cross-fade between songs in your recording, if you managed to start it at just the right moment anyway.

It's very organic, full of imperfections and character, based on what songs you were able to painstakingly line up.

And then you listen, enjoying the fruit of your work and dedication. Right up until you hit the end and either have to turn the cassette over and play the other side, or wait for it to rewind.

In time, cassettes gave way to CDs, with better audio and more storage. You could still record your own, but you got to be intentional about it. You'd arrange the playlists with exactly the songs you want, in the order you want them, pop in a blank CD, and hit the "Burn" button. A perfectly curated mix, flawless, exactly as intended.

Not saying it's any better or worse. Just different. I'm the kind of person who likes listening to an album from start to finish and get annoyed when I listen to my music library on shuffle.

Then come the MP3 players, the iPods. Limewire for getting whatever song you want. iTunes' 99¢ songs. Then Pandora with a radio station tailored exactly to your tastes. And now Spotify and on-demand music streaming of whatever you want, whenever you want it. Algorithms matching what you listen to with every other song in existence.

Again, that's not better or worse. Just different. Certainly much of the music I've enjoyed listening to started as a one-off algorithmically suggested song.

But there's something to be said for the messy, imperfect, unusual human curation of cassette tapes. Offhand, I can't think of another medium that has the same charming chaos.

This isn't to be nostalgic for the past. Truth be told, I've only ever made a handful of cassette tapes myself. But I remember as a young child the tactile sensation of putting the cassette in, hitting play, and dancing around. My child can't really have that experience with streaming music unless I put together some kind of player (or — heaven forbid — buy one of the crappy single-song players).

This is me wondering what qualities of cassettes are good and positive and constructive, and what means we have now to replicate those qualities. What can we bring back?