Rachael Ray stumps Australian actor Alex O'Loughlin, who stars in 'The Back-up Plan' with Jennifer Lopez, by testing his knowledge of theme songs to classic American TV shows on 'The Rachael Ray Show' (weekdays, syndicated).

O'Loughlin, who claims to be an avid fan of American TV, correctly belts out a line from the 'Brady Bunch' theme, but fails at 'The Golden Girls.' And, when he can't recall the theme to 'Cheers,' the audience groans, then starts to sing the song for him. "I just wanted to hear the audience sing," O'Loughlin said sheepishly.

Watch the video after the jump.Rachael Ray stumps Australian actor Alex O'Loughlin, who stars in 'The Back-up Plan' with Jennifer Lopez, by testing his knowledge of theme songs to classic American TV shows on 'The Rachael Ray Show' (weekdays, syndicated).

O'Loughlin, who claims to be an avid fan of American TV, correctly belts out a line from the 'Brady Bunch' theme, but fails at 'The Golden Girls.' And, when he can't recall the theme to 'Cheers,' the audience groans, then starts to sing the song for him. "I just wanted to hear the audience sing," O'Loughlin said sheepishly.