Turning Big into a musical makes complete sense. The scenario, in which a young boy wishes to be big and wakes up the next morning to discover that he is the same boy but in a man's body, is pure fantasy. Once you accept that, then you can enlarge the fantasy in any way you like, even with singing and dancing.
One of the film's best sequences takes place in the giant New York toy store, FAO Schwarz. Cannily, they have been persuaded to sign a major sponsorship and merchandising deal, which opens up enormous possibilities for future productions.
I can see it now. Harrods Food Hall could sponsor The Wild Duck and London Transport would be perfect for A Streetcar Named Desire. The Pajama Game is a must for Marks & Spencer, and theatreland is now ready for A Doll's House by Hamleys and The Cocktail Party by Absolut Vodka while Prozac could do the entire works of Pinter. Ann Summers could do As You Like It, the Liberal Democrats are a cinch for Much Ado About Nothing, and the Iraqi government would happily back Damn Yankees. I look forward to Sky TV sponsoring Fiddler on the Roof, but who could we get to shore up The House at Pooh Corner? Gilbert and George, perhaps? As for the revival of Moby Dick... the Maxwells?