Watch Online Free on Watchseries. Heathers the Musical, known colloquially as Heathers, is a musical by Laurence O'Keefe and Kevin Murphy, based on the 1988 film of the same name written by Daniel Waters.[1] After a sold-out Los Angeles try-out, the show moved Off-Broadway in 2014, with US producers including J. Todd Harris, Amy Powers, RJ Hendricks, and Andy Cohen.