So I am the recordist for the Russian Chamber Chorus of New York. Here's an example of how amazing they are.
This is with Adrian Daurov on cello and Mikhail Zeiger (who arranged this piece) on piano. The conductor, Nikoli Kachanov is simply brilliant. He's one of those certified geniuses. You could learn more from him just being in the same room for half an hour than studying for a dozen years in college.
Hearing the RCCNY is a spiritual experience.