lol, now ya asking!!!! Fook knows....I'll look for you now....
Right, under settings (little cog image on ibluetooths home screen) scroll to the bottom and theres a section for showing 'save path' and 'FTP Root Path'. I havent edited my settings, so mine reads
Var/Mobile/Documents Try tapping the 'File System' Tab at the bottom of the ibluetooth homescreen and tapping the little folder icon on the top right hand side
If its an .mp3 file tho, you may need another music player like
dTunes to play it, being as Apple are stupid