The screenplay for The Wiz was written by Joel "bat-nipples" Schumacher, by the way. It's not the black version of The Wizard of Oz--it's the blaxploitation version of The Wizard of Oz. I saw this movie at the theater (it was actually rated G) as a kid and I remember being shocked at how sleazy and off-putting much of it was. I was a fan of Michael Jackson but I thought his scarecrow makeup was hideous. I see it's on Netflix, so I'll have to see if it's really as bad as I remember.
I also saw a trailer for The Apple as a kid, too (possibly when I saw The Wiz, now that I think about it) but all I could remember about it, really, is that it was lurid and strangely alluring. Finally caught the trailer again on U2b a couple of years back. Yeah... Bad. But I think Carousel is Rifftrax material, and that's considered a classic musical, so results may vary.