I am assuming this will moved to the apps forum. But to answer, I cannot say enough how much for me it is worth the money. You have access to virtually any album that is released, it is organized perfectly, you can create any playlists that you want, etc.
Now you can see artist biographies, you can see when and where they are touring, you can search by song album artist. I love that you can download any songs you want locally so that you can play without streaming. And with the Discover feature, along with the Radio, you are always able to discover new music.
I apologize, because I could go on and on. It is easily the best $10 a month that I could ever spend.