I first saw Hot Tuna in the mid-1970s in New York at the old Academy of Music on Union Square, aided by spiked Kool-Aid backstage and an inspirational roommate from Brooklyn named Joshua Dratel. Josh worshipped Jorma Kaukonen, studying 12-string guitar, listening to the blues of Kaukonen's teacher, Durham's own Rev. Gary Davis, and catching me up on old Jefferson Airplane. So I had no idea what to expect. The amalgam of electric and blues, San Francisco and Piedmont North Carolina, was a revelation. Kaukonen is one of the best guitar players alive today, and the chance to see him with best friend and brilliant bassist Jack Casady for two acoustic sets Friday night at the Lincoln Theatre isn't just a trip (no pun intended) down memory lane, it's the chance to see the embodiment of some of the greatest music America has ever produced. Kaukonen and Casady are national treasures, up there with Bob Dylan, but they're still playing close to their roots in rock halls like the Lincoln and down-home festivals like Merlefest. Catch them there while you can. Tickets are $20 in advance, $25 day of show; www.lincolntheatre.com.