Two books of Duncan’s songs have been performed and recorded by the cream of singers. Cleo Laine, Blossom Dearie, Mark Murphy, Sandra King, Norma Winstone, Elaine Delmar, Marlene Verplank, Daryl Sherman, Joyce Breach, Richard Rodney Bennett, Frank Holder, Nancy Marano and Natalie Cole. He has earned the respect of some of the most important people in music as a player, writer, arranger and composer, including Benny Carter, Johnny Mandel, Marty Paich & Claire Fisher.