Here is Gondoliere, the best app to get all the music you want.
Just search for any artist or song, and Gondoliere will show you the matching results.
Click on them to get them downloaded on your device, so you can listen to them even without internet connection.
Check for further instructions on the app.
Note: music is provided by "www.jamendo.com". All songs, available through this application, are intended only for your personal non-commercial use.
Since the music is from authors who give their music for free, you won't find any commercial music here. Please don't give negative ratings just because you don't find what you want.