Stephen Sondheim’s dark melodrama Sweeney Todd(1979) is undoubtedly his meisterwerk. No one has done more to singlehandedly advance the cause of the American musical than Sondheim and although his output during the 1970s is remarkable for its breadth of topics and milieux and innovative in terms of influence and structure, both Folliesand Pacific Overtureswere initially failures, growing into cult favourites as the years passed. Many fell for the sophisticated Nordic blues of his Bergman operetta, A Little Night Music, but nothing would really prepare his audience for the dark, revenge filled fury of Sweeney Todd. Based on a Victorian serial, A String of Pearls, in a muck-filled penny dreadful, the well-known tale of the ‘demon barber’ and his pie baking accomplice would raise the composer’s interest as a play by Christopher Bond during a mid-70s London sojourn.

Sweeney Todd Ben Mingay and the cast of  Sweeney Todd. Photo © Soda Street Productions

Is it a musical or an opera? Classification doesn’t really matter as the show has worked equally on Broadway, in the opera house and on...