De Haas will perform selections from such musicals as Les Miserables and Porgy and Bess, along with pop music by Billy Joel and others. Flack, a Grammy Award-winning singer and songwriter, is best known for hits such as "Where Is the Love?" "The First Time Ever I Saw Your Face," and "Killing Me Softly (With His Song)."

De Haas has appeared on Broadway in Carousel, Rent, Marie Christine, and The Gershwins' Fascinating Rhythm, as well in the Actors' Fund benefit concerts of Dreamgirls and Hair. He has performed at Jazz at Lincoln Center, with the New York City Gay Men's Chorus, and will take part in a tribute to James Brown on September 10 at Birdland.