There can be several reasons, depending on the type of audio played (mp3, audio CD?). It can be influenced by mixer settings, the output plug-in or possibly some others factors outside of Songs-DB. Can you give some more details?
Sometimes problems are to stupid they solve itselves
I didn't put the CD in the PC!
I didn't get a warning 'no CD' or something and only saw the title running.
No music with no CD seems logical