Could you help me understand here?

I know you can make a Spotify playlist of content hosted via Spotify. You can also add your own locally-provided (e.g. mp3) content to this playlist. But can you also add content from a different streaming service to your Spotify playlist?

Could you merge Spotify tracks with, say, Bandcamp tracks on a single playlist?

Doesn’t Winamp already do this?

I used to keep the portable version on a flash drive with a few dozen of my favorite tracks. Such a fantastic player.

Yeah, gotta search for the full “simply Lemmy but as a webapp” in order to actually find the right thing