I read this the other day and saved it. It pretty much answers the question in one of the best ways I have ever heard it put:
Bluegrass Music is a shivering, blustery Friday night on the Ohio, at a town called Owensboro waiting to hear more...
As they begin, the cold and wind vanish, and all you hear, all you feel, is the music - true and sweet. It is the campfire where we gather, listening and playing. Ordinary people go from camp to camp, carrying their instruments, bringing their music, sharing their friendship.
It is the Mother with her ancient guitar and her Son with his beat-up bass, playing together, singing together, stirring everyone who hears. It is the first rays of light as you hear the far-away strains of gospel music on a Sunday morning.
Bluegrass Music is actually meeting Doc Watson. It is leaving your chairs in the same place for three days, knowing they'll be there when you come back. It is a mandolin player making giant sounds with a tiny instrument. It is hearing a group of young people play sweet music from their hearts, just for fun. Laughing, joking, enjoying life. Bluegrass Music is Jerry Douglas on stage, alone, mesmerizing an entire crowd with his artistry. It is a fiddler making tears come to my eyes. It is looking at my wife, my mouth hanging open, saying, "Did you hear that?" It is Tony Rice playing, playing, playing...magically. It is smiling so much your face hurts.
This is Bluegrass Music, this and more. It is almost a way of life, a respite from everyday rushing and hurrying. A chance to get back to yourself, a chance to meet old friends and make new ones. A chance to celebrate life. A chance to thank God.