Francis Davis’ inspired The History of the Blues includes an anecdote in which the author, lost in the D.C. suburbs during a thunderstorm, hears O.V. Wright on his car radio: “As Wright’s screams rent the air and the nameless DJ cut in between the tracks to reiterate what Wright had just said, there was no place I would have rather been than lost on the road in that Toyota, with the rain falling down.” As a ’70s soul singer, Wright isn’t even mentioned in most blues surveys, but Davis’ personal and idiosyncratic history shuns pedantic definitions (as well as the standard blind worship of the Delta style) to celebrate the blues’ fierce grip on this century’s music and culture. The book also serves as a writerly companion to the PBS series of the same name. A contributing editor of the Atlantic Monthly, Davis reads from his new work at 6 p.m. at Vertigo Books, 1337 Connecticut Ave. NW. FREE. (202) 429-9272. (Eddie Dean)