> Most don’t allow me to augment their catalog with stuff I own, and stream it back to me via a unified interface. Spotify on desktop (at least on Windows) let

> Most don’t allow me to augment their catalog with stuff I own, and stream it back to me via a unified interface. Spotify on desktop (at least on Windows) lets you select some folders on your HD and adds them to your "collection". You can then play them thru Spotify. If they have ID3 tags, they get correctly tagged and you can click the artist name to go to their page. If you create a playlist with some local files in it, and download the playlist on a smartphone (while the pc is on), you have those files available there too. It's pretty convenient.