Hiya Raz!
We usually just have the radio playing in our shop - we're lucky here in Chicago with a wide variety of stations.
But if you're so inclined, I'd recommend Google Play (paid version). I've got it and it doesn't disappoint. I've never tried Pandora or Spotify, but I've been told it's about the same, but with more full albums.
Also, Ryobi makes a great, cheap little shop radio with Bluetooth - I highly recommend.
(I'm not a paid spokesperson for Ryobi or Google -
)