The difference in tiers is all about access. All Prime members will be able to access the entire Amazon Music catalog, but not fully on demand; you can shuffle any artist, album, or playlist, Amazon says, but you can’t just select a song and hit play. For that — and to play songs in higher fidelity or with spatial audio — you’ll need a $9 monthly subscription to Amazon Music Unlimited. (A few playlists will be available on demand and for offline listening to non-upgraders, Amazon says, but it’s not clear which ones.) As free services go, though, Amazon Music is now essentially Spotify minus the ads for anyone already paying for Prime.