PREVIEW Oh baby, baby, baby, have you got them blues? I did, big time, a couple weeks ago after ODing on the metal and all its scenesterness. I nearly wrote off going to shows entirely. This silly sentiment lasted one hot minute, sure, but the blues remained. The blues remained. The blues remained. Which is the point: get rid of any genre-defining accoutrements — country's twangs, metal's sweeping arpeggios, jazz's swanky chords — and you're left with the 1-4-5 progression made so familiar and beautifully basic by early 20th-century blues masters.

So if you're feeling especially bummed, love the blues, or are a music junkie in general, this weekend's 36th annual San Francisco Blues Festival is mandatory. Holding the title of the oldest blues festival in the world, its lineup of legends attests to its status as an institution unto itself. Performers include electric slide virtuoso Johnny Winter, now in his fifth decade of performing, and David Honeyboy Edwards, who at 93 is one of the last Mississippi bluesmen of the Robert Johnson era. Maybe he'll bring the devil and you can bargain your soul for six-stringed genius at the evil-brewing crossroads of Buchanan Street and Marina Boulevard.

Besides dancin' and groovin' to more than two dozen artists, you'll get to hang outside for three days (weather.com forecasts sun, for whatever it's worth), which also tends to assuage the blues — although instead of a background of railroad trains and Delta mudflats, we get the Golden Gate Bridge and a scintilutf8g Bay. Throw some horns for Robert Johnson's legacy.

SAN FRANCISCO BLUES FESTIVAL Tribute to John Lee Hooker. Fri/26, noon–1:30 p.m., free. Justin Herman Plaza, 1 Market, SF. Sat/27 with Hot Tuna, the Delta Groove All-Star Blues Revue, Barbara Lynn, Michael Burks, Ruthie Foster, Elmore James Jr., and Delta Wires Big Band. Sun/28 with Johnny Winter, Buckwheat Zydeco, Curtis Salgado Big Band, David Honeyboy Edwards, Rick Estrin, and Gospel Hummingbirds. 11 a.m.– 6 p.m., $40 per day. Great Meadow at Fort Mason, Marina at Buchanan, SF. (415) 979-5588, www.sfblues.com