AllMovie

The Under-Pup served to introduce Universal's new preteen songstress--and potential Deanna Durbin replacement--Gloria Jean. Producer Joe Pasternak sagaciously based the leading character on Jean herself: A shy, self-effacing 11 year old girl, thrust into a glamorous lifestyle beyond her ken. She plays a small-town thrush who wins a music scholarship to a fancy Interlochen-style music camp. Her rich classmates snub Jean at first, but she wins them over with her indefatigable good spirits and her angelic singing voice. While The Under-Pup made Gloria Jean a star, she never did become the new Deanna Durbin as planned--partly because the old Deanna Durbin still had a decade's worth of movies left in her.