Oh, Tom Dooley (Dula, really), I guess. Thence the Limeliters. Chad Mitchell (Lizzie Borden!Super Skier!)With and without the young John Denver, ne Deutchendorf!)Then PP&M, Bobby D, Woody, Pete, and off into the roots and branches. One nexus I haven't seen explored is the barbershop-Four Lads,Kirby Stone Four, Four Freshmen, Lettermen-Kingston Trio (and, in another direction, Beach Boys)- harmony trail.Sometimes our hands and strings push our voices out of the mix, which is too bad: I like a good country third-and-fifth as much as anyone, but there's fun to be had without turning into the Swingle Singers. (Joe Queenan refers to Riverdance as Celtic hopscotch,but he's about the meanest man now writing.)