Gramophone : MOAR!!! material design
Gramophone is a music layer targeted at this user base. In terms of functionality it brings nothing new to the table. Where it stands out is in it's design. It does a great job implementing material design, and the interface is fresh and intuitive.
I realize that I'm making it sound like I'm recommending it just for it's aesthetics, but it has all the functionality most need, and then some.
It has Last.fm integration and even has a built in ID3 tag editor to edit details of tracks. It also works with AudioFX on CyanogenMod. Gramophone has a homescreen widget, but I had trouble getting it to work for me.
Gramophone is free, but is in closed beta right now. If you want in on the action, you have to join Gramophone's G+ community to download the beta.