Spotify has several ways to discover similar artists/genres you enjoy.
1. "Fans Also Like" on the artist page
2. Use "Go To Radio" and it will play similar artists within the genre of the song you are listening to
3. Spotify can build playlists based on your tastes or genre
4. Smart Shuffle infuses similar artists/genres into your current playlist
5. Following artists you like will push similar artists into your feed
This is one of the main reasons I prefer Spotify. And with the premium account, it's lossless audio.
Pandora is not supported for a reason. It's like the AOL of email addresses.
As @gkelly suggested, get the WiiM. I purchased a WiiM Amp: Multiroom Streaming Amplifier for my non-listening room and it works flawlessly for both TV audio and music streaming.

