Amazon Prime Music is great. I can find most of what I want to listen there. The only thing that gets to be a bit annoying is when you search for popular music and all that is available is cover versions or live versions or no version at all. Amazon has just launched a new music service called "Music Unlimited".
Music Unlimited will directly compete with Apple Music, Google Play Music and Spotify to give you on demand access to tens of millions of songs. This is a service in addition to Prime. Prime members will pay $8 per month or $80 per year while those without a membership will pay $10 per month. Those who own an Amazon Echo will pay only $4 per month which happens to be the cheapest music streaming option on the market. There is also a family plan for $14.99 per month or $149 per year. They are currently offering a free months trial.
via Amazon