By turns focused and restless, jazz reedman and composer Henry Threadgill has blurred the lines between free improv and structured composition since he first emerged as a bandleader in the mid-'70s. “Air Raid” finds his trio Air careening between raucous outbursts and calm restraint, while “Spotted Dick Is Pudding” staggers along like a drunken blues march, and Threadgill's Pulitzer-winning composition “In For a Penny, In For a Pound (Opening)” melds a century of African American music into a stunning amalgam.