Laurie Anderson is performing a show titled “ublicublic of Love” at Central Park SummerStage on June 26, as part of the 40th-anniversary season of the City Parks Foundation’s outdoor concert series. She’ll be backed by Sexmob, a downtown jazz band that grew out of the free-improv scene around the Knitting Factory in the 1990s, and she’ll be singing songs of hers in the midst of other contributions by fellow American visionaries like Bob Dylan, Lou Reed, John Cage, Gertrude Stein, William S. Burroughs, and Allen Ginsberg in what she’s calling “a celebration of freedom.”