After reading Dennis McNally’s biography of Jack Kerouac, “Desolate Angel: Jack Kerouac, the Beat Generation, and America,” Jerry Garcia invited McNally to become the Grateful Dead’s historian. In 2002 he published his long-awaited chronicle of the band, “A Long Strange Trip/The Inside History of the Grateful Dead,” which later appeared on the New York Times best-seller list. In the interval he’d become the band’s publicist, working on its behalf at the United Nations, the White House and Congress. His third book, “On Highway 61/Music, Race, and the Evolution of Cultural Freedom” (2014), told the story of what white people learned from African American music. It won ASCAP’s Deems Taylor/Virgil Thomson award. He later published an edited version of his interviews with Garcia, “Jerry on Jerry.” His current book-in-progress is “The Last Great Dream/How the 1960s Counterculture Came to Be.”