Carrie Underwood was taken aback by an American Idol contestant - not for the first time this series - and found herself singing along to her own anthem, "Waiting All Day For Sunday Night." The 2005 American Idol winner is now a judge on the hit show and was treated to a rendition of her famous song,

An insider alleged that the 'American Idol' Season 23 crew was told not to discuss Carrie Underwood's inauguration performance.

Carrie Underwood was surprised by an American Idol contestant and left singing along to her own anthem, "Waiting All Day For Sunday Night." The 2005 winner of American Idol was treated to a rendition of her famous song,