It doesn't say "KARAOKE" or "CDG" on the play screen either, simply "USE CDROM DRIVE" or " USE HARD DRIVE". You can play a cdg or a wav from the use cdrom option. We mostly all just assume it will only play cdg.
I never have figured why there isn't a .WAV/.cdg play option, since you have the choices on the import, custom assembly, and duplicate disc tabs, and you can play a .WAV from the cdrom drive, but not the hard drive.
You figure
George