The Banshee is default music player which replace Rhythmbox on the next ubuntu 11.04 Natty Narwhall, is called banshe give more advantages than Rhythmbox such us listen to the internet radio, easy to organize audio library, view the Wikipedia entry for the playing artist, similar artists and albums, and much more.
Banshee is available from the official Ubuntu repositories; click here to install it or you can download banshee source installer here http://banshee.fm/download/.

Banshee screenshoot
Install banshee via apt-get install
you can also install banshee from APT or ubuntu software center, this is Banshee repository provided by PPA Launchpad which can be add to your repository
   ppa:banshee-team/banshee-daily
Install Banshee on ubuntu via apt-get through this command
   apt-get install banshee