Unlike many critics who see jazz as one big logical, evolutionary continuum, Scott DeVeaux sees bebop as a revolution whose impact was as much social as musical. Unlike numerous other bebop histories, DeVeaux’s The Birth of Bebop concentrates extensively on the swing and post-swing years that birthed the music and discusses the shifting cultural landscape that was exploding around it. The associate professor of music at the University of Virginia discusses his new book today at noon at the National Archives Theater, 7th & Pennsylvania Ave. NW. FREE. (202) 501-5000; and at 7 p.m. at Borders, 18th & L Sts. NW. FREE. (202) 466-4999. (CP)