I love that (Canada's own!) Norman Jewison did Fiddler and JCS back to back--since they are both so different. I LOVE both--I know JCS divides fans of that show sharply, but oh well. I also think they are the peak of Jewison's career (although I am personally very fond of Agnes of God, as well.)
Fiddler is an interesting case, I think. It opened over half a year before the show closed on Broadway which (I think?) was pretty rare, especially back then. Robins' production was so iconic but, with the revolve and Aronson's gorgeously stylized Chagall-inspired sets (which initiated his great, long career with Hal David until his death,) it's so innately theatrical. And, unlike Jewison's JCS, or even some other Jewison movies (the stylized camera work of Thomas Crown Affair, for example,) the film is very, for lack of a better word, theatrical. There is next to no stylization to try to capture any of the play's theatricality. And, in this case, that really works-- (Tevye does address the audience but since he's kinda speaking to God, it works.)
Joseph Stein adapted his own libretto, and from what I can recall kept a LOT of the stage dialogue (I don't miss The Rumour really, but I do miss Now I Have Everything.) I think he makes the Beggar a mute, as well, and there are a few added scenes that "open it up." I like the added song Any Day Now on the soundtrack and wonder if it was filmed (and how horrific that the late 70s reissue cut 40 minutes including Far From the Home I Love and, of all things, Anatevka.)
The film was a BIG hit, but it often seems oddly to get forgotten in survey discussions of the ups and downs of film musicals. Critics often talk about how, after Sound of Music in particular, the studios all tried for fancy, "road show", expensive musicals (original and Broadway adaptations,) that mostly lost some or a lot of money (Sweet Charity, Camelot, Chitty Chitty, Dr Doolittle, Star!, Hello Dolly, and so on and so on.) And then they skip ahead to the groundbreaking style and success of Cabaret, sighting it as a different approach to adaptation. But they tend to skip the fact that in 1971, Fiddler was a big road show adaptation of a stage musical (mind you done in a gritty, realistic style at odds with most of those other films--and at odds with the brightly coloured stage version,) and was a massive critical and audience success. Still, its success didn't really seem to lead to the studios reconsidering after all the recent flops, returning to more musicals.
And this thread reminds me I really need to pick up the blu ray which I see contains the National FIlm Board of Canada's documentary Norman Jewison, Filmaker which I remember being fascinating in following the filming process.