DioGuardi rose to prominence as a songwriter for popular musicians like Kelly Clarkson, Christina Aguilera and Pink. Her public profile increased when she joined the judging panel of American Idol for two seasons in 2008 and 2009. After leaving Idol, DioGuardi served as a judge on the song-writing TV competition series Platinum Hit. DioGuardi, a singer herself, released her memoir A Helluva High Note shortly before making her Broadway debut as Roxie Hart in Chicago.