I've often mourned the fact the singing in American culture has become a solo act rather than a communal experience. I think one of the most profound differences between American theatre training and UK training, is that most British theater troupes sing together regularly either within productions or just part of the warm up/rehearsal process. Singing together teaches intuitively about listening and responding to one another- both individually and communaly- it binds people. Certainly the church needs that, but for some reason, most led music in US churches doesn't achieve that group experience- it's the "feeling alone in a crowd" thing- which totally disappears once the music becomes a cappella- you hear each other. I love this- and have used it a lot this year in worship planning- a cappella all the way baby!