Old Crow Medicine Show will headline a lineup of 12 bands performing at Cumberland Caverns this weekend as filming for season three of the Bluegrass Underground TV series takes place over three days.Production crews will begin setting up today for performances that start Friday night at 6 p.m. Music begins at 2 p.m. on Saturday and Sunday.“It’s like Bonnaroo 300 feet underground,” said Bluegrass Underground producer Todd Jarrell. “Bluegrass Underground has become an event and it’s very cool how it has become an event. People come from all over the country to see it.