I sing with a group called Collegium Cantorum, a small, eclectic group of singers led by a man with a Tolkien-esque beard and a remarkable passion for Renaissance polyphonie (i.e., sacred music from 12th through 15th centuries). The music is beautiful and, like yoga, deceptively difficult -- it requires enormous concentration and control to do well.
But in addition to the music, the people are a hoot. Here's a typical exchange during rehearsal:
[Timothy, the director, stops the chorus after a particularly rough passage. He points out an interval that the tenors missed.]
Charlie (a tenor): Oh, that's the Klingon fifth!
Timothy: That's right. As some composer said, "If it worked once, why not use it again?"
Mike (a bass): Hey, it worked for Thomas Hardy.
Tonya (an alto): And Dickens, too!
How many groups of people do you know of who can go from a 15th century Latin mass to Charles Dickens, passing through Star Trek, in five moves?