Choirs are interesting.  They are also known as a quire, chorale, or chorus.
Are you talking about the groups with a large amount of people singing different tones and ranges to make a song?
Yes indeed.  They may perform music from a classical music repertoire.
Oh wow.  What's your favorite classical song?
I have a few, and seeing choirs being led by conductors is an amazing scene.
My favorite classical songs have to be anything by Bach
Bach is a classic.  Born July 28, 1750.
My birthday month is also July.  I also enjoy Meredith Monk
That's cool, actually she was born November 20, 1942.  She's a composer and many other things.