Do we really need another slim volume on the great Stephen Sondheim? Along with innumerable reviews, essays, and articles, we have Craig Zadan's account of Sondheim's early career, Sondheim & Co (1974), Meryle Secrest's Stephen Sondheim: A Life (1998), and the promise of a definitive biography from the critic David Benedict. If that were not enough, we also have Sondheim's conclusive reflections on his oeuvre, Finishing the Hat (2010) and Look I Made a Hat (2011). To add to the mix, organisations like the American Sondheim Review and the British Sondheim Society and websites like sondheimguide.com keep the aficionado up to date with all related Sondheim productions and materials. A 2015 recipient of the USA's highest honour, the Presidential Medal of Freedom, Sondheim (now eighty-six) is the most lauded and written-about living theatre practitioner in America.

Ethan Mordden has titled his work On Sondheim: An Opinionated guide. Anyone who is familiar with the works of the prolific Mordden will be aware that the adjective in the title is redundant. Mordden has made a career out of being the most adamant person in the room. On subjects ranging from opera recordings to American theatre to gay history, Mordden is never shy about sharing his viewpoint. His major topic is the American musical theatre on which he has written a plethora of books and articles.