Virginia pickers Old Crow Medicine Show took old-timey bluegrass and injected it with rock ‘n' roll energy in the mid-'00s, helping to rejuvenate the genre. That's in part thanks to their signature song “Wagon Wheel,” a sinewy, banjo-fueled road yarn of Bob Dylan's that the band put finishing touches on. But their modern take on age-old traditions is plain irresistible: The rowdy, harmonica-blown ramble of “Cocaine Habit” is perfect for a hoedown, while the slide guitar simmer of “Down Home Girl” captures simmering Southern summers.