The music streaming business has just gotten even more crowded. Although no stranger to streaming music, Amazon has only offered a rather limited catalog via its Prime-exclusive Amazon Music service. Now, it is directly taking a bite out of Spotify’s and Apple Music’s pies. Offering “tens of millions” of songs, Amazon Music Unlimited is might have a bit of trouble squeezing itself into the crowded space. But it has one ace up its sleeve with a cheaper but somewhat more stationary “Echo-only” subscription.