Music collection quits,k but radio works -- help

[smithtravel]

Don't flog me, please. I did search, just can't find this problem anywhere: My music collection has stopped playing. Both radio and CD work fine. Music collection will show the songs on the screen, but won't start playing. Had problem two weeks ago, turned off car and restarted. Problem solved (almost like rebooting a computer). This time, no luck with that. Anyone else have this problem? Thanks.