The sold-out show will also feature performances by Sammy Hagar, Shawn Colvin, Richard Marx and Train's Pat Monahan. The Wilson sisters will sing an array of holiday songs written by Joni Mitchell, Harry Nilsson, Bob Dylan and Hagar in their Christmas set as well as some of Heart's favorite songs. Colvin, Hagar, Marx and Monahan will provide additional vocals on the tunes and/or sing duets with Heart.