While this all sounds like a warm and fuzzy nostalgic trip, big music didn't like us doing this when we made mix tapes off the radio.

Spotify certainly doesn't like it and it's second only their prohibition on reverse engineering their own software in their User Guidelines.

  The following is not permitted for any reason whatsoever in relation to the Services and the material or content made available through the Services, or any part thereof:
  2. copying, reproducing, redistributing, "ripping," recording, transferring [1]

It's surprising that a Spotify developer would not only write this up but also self post it to HN. Is there some performance review metric tied to how influential you are for the company or something?

[1]: https://www.spotify.com/us/legal/user-guidelines/#:~:text=co...