Look who is uncredited on Sister Whiskey's album

Backing Vocals [uncredited] – Glenn Hughes
Bass Guitar, Backing Vocals – Rich Florio
Drums, Backing Vocals – Gregg E. West
Lead Guitar, Backing Vocals – Tyler Gentile
Lead Vocals, Harmonica – Dennis Lee Duncan
Producer – Dana Strum
Rhythm Guitar, Backing Vocals – Jack Aurora

Actually, he has never recognized to have sung in this album. And if you listen to the full album it's difficult to recognize his voice.