In the summer of 1999, the Hot Buttered Rum String Band set out to rediscover the high lonesome sound of mountain music from the Sierra Nevadas, a style they called "high altitude bluegrass." A decade and a bit later, after years of near-constant touring, the group has evolved into a plugged-in, rocking powerhouse that blends jazz, country, and world music into its tasty, percussive mix.