Murney's Off-Broadway theatrical credits include originating the role of 'Queenie' in Andrew Lippa's The Wild Party at the Manhattan Theatre Club, opposite Brian d'Arcy James, Idina Menzel, and Taye Diggs, for which she was nominated for a Drama Desk Award. She was also seen in The Vagina Monologues, Crimes of the Heart, A Class Act, Time and Again, and First Lady Suite. She appeared in a musical version of the film Saved at the Playwrights Horizons Theatre, which had previews starting from May 9, and an opening on June 3, 2008. In August 2008, Murney portrayed the title role of Andrew Lloyd Webber's Evita at Wells Fargo Pavilion in Sacramento.
Murney made her debut on Broadway in 2005, in the short-lived musical Lennon. She was also seen in the Actors' Fund benefit concerts of Funny Girl, Chess, Hair, and the World AIDS Day Benefit Concert Pippin. She has also been featured on television in Sex and the City, Ed, NYPD Blue, and various episodes of Law & Order.
Murney starred as Elphaba in the national touring company of the musical Wicked. She replaced Stephanie J. Block on March 8, 2006 and left the National Tour on September 3, 2006 replaced by Shoshana Bean. In that role, she won an Acclaim Award from the Cincinnati Enquirer for leading performer in a musical. She recently reprised her role as Elphaba in the Broadway production replacing Ana Gasteyer and ended her 8-month run on October 7, 2007, where she was replaced by Stephanie J. Block.
Her debut solo album, I'm Not Waiting, was released in May 2006 on the Sh-K-Boom Records label. The album's title song was written especially for her by Andrew Lippa, with whom she has a strong artistic relationship. Murney also sings a jazz acoustic version of the song "I'm Not That Girl" from Wicked. She can also be heard on the original cast albums of The Wild Party and A Class Act, and the Actors' Fund recording of Hair.