I'm working on a short documentary project that will involve recording a small group of musicians rehearsing--I'm talking about un-amplified classical music here. I've recorded music in an amateur context before, but recording live music is not my area of expertise. I want to make sure I get as good of a live recording as I can for these sessions. Any suggestions in terms of mic technique or setup?
[Tarik Fouda]"Any suggestions in terms of mic technique or setup?"
Too much depends on the space they are playing in, the musicians themselves, the music they are playing, the instruments they are playing. Since you haven't described any of these things, we can't begin to guess at what you might need. How I'd want to record a Bach cantata in a big stone church is completely different than how I'd want to record a Beethoven piano sonata in a compact performance hall. And both are completely different than recording in a relatively dead practice space.
A place to start might be a book like Ricard King's Recording Orchestra and Other Classical Music Ensembles.