I've been listening again to Sweeney Todd (the Cariou/Lansbury recording) and was again struck by the brilliance of one particular scene. Todd has the hated Judge in his chair; they exchange ordinary barber-customer conversation as Todd lulls his victim into security, through with the audience's tension gradually mounts in expectation of Todd fulfilling his obvious murderous intentions. Sondheim then, quite brilliantly, has them sing Pretty Women, a tender duet about the only thing they could possibly have in common (the Judge pursued Todd's wife and is shortly to marry his daughter) - Todd gets wrapped up in the moment and almost forgets himself. However much they hate each other, and however bitter and twisted they both are, they still share this same warmth; expressing it in this way - and, almost as a by-product, ratcheting up the tension almost unbearably - and at this time nothing short of genius.
It also reminded me how powerful musicals/opera can be. I'm trying to switch from libretti to a novel, and there are a lot of things which are much easier in novels, but there are also some things which simply cannot work on paper. The above is, for me, a definitive example. I recognise that I could not write anything approaching this no matter what the medium (frankly, few people can), but it has reminded me that while I have a stack of new tools at my disposal, I have also put a stack of others away. Ages of Man could never work as a musical and would require a rather different approach to work as a play, but a few musical numbers in the novel would solve a few problems!