You /might/ be able to find Spotiamb. It was a Winamp like Spotify client written by a Spotify developer when they used to support libspotify. Obviously Spotify have killed all libspotify development now and I don't know if Spotiamb even works now.

There is librespot [1] if you want to try and do something yourself though, it's a reverse engineered client for Spotify's protocol which Spotify so far doesn't seem to care to kill off.

[1] - https://github.com/librespot-org/librespot