When Broadway first became, well, Broadway its style was the popular music of the day. This continued through the thirties, forties, and into the fifties, when pit orchestras differed little from popular "big bands". As rock and roll gained in popularity, show tunes remained much the same. With few notable exceptions, efforts to marry rock music with the musical theater were disappointing. Things really didn't change much until the eighties and nineties. And when they did, Broadway began to take off again.
So, what was this change? I think each style gave a little to the other. Pit rhythm sections grew (both in the number of musicians and their importance to the score). Hit records became more elaborately scored (borrowing elements from classical music, as well as jazz and the big band era).
Listening to shows composed in the last twenty years or so, I feel like a new Broadway style is emerging. And, to my ears (which are admittedly aging and perhaps not as well versed as they used to be) it sounds most like pop music. Pop, as opposed to rock, or rap, or heavy lead (er, I mean, metal). A lot of show tunes these days remind me of soaring pop ballads. And the production numbers sound a lot like the tracks my nieces are listening to on their iPods (or iTunes).
I'm just wondering if others, who have had more exposure to pop music and Broadway than I do, feel the same and what that means. Generally, I feel it's a good thing. It means that musical theater is thriving (taking and giving back to pop culture) in the way that at one time it seemed to have forgotten. On the downside, I find that a lot of numbers I've heard from more recent scores seem a little too similar (almost interchangeable, in some cases). Maybe it's just me, but I seem to remember a time not so long ago when there was more variety. I hope we are not sacrificing that. (I wouldn't want the next MAN OF LA MANCHA to sound like the next RENT or the next SUNDAY IN THE PARK WITH GEORGE.)