I agree with gypsy. Popularity and impact on musical theatre as an art form are 2 wildly different things. There is also a very big difference between general cultural impact and impact on musical theatre as an art form. As much as I don't like ALW, I'd be willing to admit that he has had a strong cultural impact. Many of his musicals have become iconic over time, and definitely hold a considerable place in popular culture, just as some of the composers you mentioned did.
It's another question entirely, however, to claim that ALW has had a significant impact on the shaping of musical theatre as an art form, in the way that Gershwin, R&H, Sondheim, etc. have. I know it's debatable, but to be honest I think that statement might be stepping over the line from "controversial opinion" to "objectively incorrect."
Updated On: 11/10/16 at 06:29 PM