I was playing 'If I were a rich man'. I noticed how it makes use of alot of notes outside its scale even though it's in C major. and I was wondering what the term is for what is it doing. Is it borrowing, modulating, using some kind of mode, or doing something else. In the main verse, I think it's getting the notes from its parallel minor scale as it sounds minor sometimes, and then at 0:40 I think it modulates to its parallel minor. But maybe I'm missing something..
It's 'In C major' the same way Beethoven's 5th Symphony is 'In C Minor' or Wagner's Ring cycle is 'In Eb'. C major is home, but it goes plenty of other places too!
Yes, there's a consistent harmonic feature of contrasting C major and C minor, and in the 'middle 8' doing the same with F minor and F major. Quite a few touches of the bII note, characteristic of Jewish music too, though it never quite goes full-blown Klezmer!
(Incidentally, the show score and original cast recording are in Db, though in the movie, a somewhat older Topol takes it down to C. Quite a shock when you've been used to the 'songbook' version and someone throws you the vocal score to play!)
It switches back and forth between the major key it starts in and the parallel minor. I think that’s what gives it that sort of klezmer feel.
No word is besserwisser safe, but I would say that it modulates between C major and C minor. https://en.wikipedia.org/wiki/Modulation_(music)