Не путать с Morrison, Gregory !
(born 1965) is an Tony Award winning and Drama Desk Award winning Canadian writer and composer best known for his work on the music and lyrics of The Drowsy Chaperone, which he wrote with Lisa Lambert. He also has extensive credits directing and musical directing shows across the United States, and Canada.[1] In addition he is a recipient of a Canadian Comedy Award, and a Sterling Award for Original Composition.

Возможно, что писатель - полный тезка с композитором