The purpose of theatre, we are told, is to push boundaries. But when it comes to musical theatre, it seems that almost no subject is too strange. In 2001, the multiple Tony Award-winning Urinetown (2001) was a scathing satire on private/public lavatory provision; while in 2017, the Donmar Warehouse staged Committee!, a musical based on the findings of a 2015 select committee that examined the collapse of the charity Kids Company.