Robert DeCormier is an American musical conductor, arranger, and director, and a graduate of the Juilliard School. He has arranged music for many singers and groups, including Harry Belafonte and Peter, Paul, and Mary, and has worked with Milt Okun. DeCormier is perhaps most famous for his spiritual arrangements.here is an a cappella setting of the Sacred Harp melody 'Wayfaring Stranger' which has been part of the choral repertoire for many years. If you haven't performed this recently, do it now! There is a delightful vocal jazz choral setting of the classic Dixieland favorite 'Ja Da.' A real crowd pleaser for any concert! The classic spiritual 'JA-DA' should be in the library of every high school choir. Sure to inspire your audience and students alike!