I am a new Ubuntu user as of this morning. I put a few songs into Banshee to test it out. Initially it didn't work, but after a reboot, it played music until I closed the app. Some time later I tried it again, and this time it doesn't play anything. Have been trying it a while now.
As far as I can tell the songs are there. They were donloaded to the hardrive and worked once today for a brief time. I don't know what the "package for the mp3 installed (ubuntu-restricted-extras)." sorry - I am a bit of a novice. Spent my computing life being coddled by Mac.