JD5Live (John) has just this moment sent me Sd Jukebox version 5 bless him so I'll have a go with it on my desktop computer and see what happens. My laptop is missing at the moment but when I loaded Jukebox v2.4 on it strangely enough it just worked and with the SD Card just in the SD Card slot of the laptop...weird.
I wouldn't mind betting that I've got a KN7000 audio version of the song you want to back your singer with - as a matter of interest what is the song?