On the Rocks gathers the highlights of David Carbonara's incidental music from Mad Men's fourth and fifth seasons, as Don, Peggy, Pete, Joan, and the rest of the Sterling Cooper Draper Pryce crew headed into the late '60s. As usual, Carbonara's music is a period-accurate and sophisticated mix of breezy, lounge and jazz-inspired cues ("Pacific Coast Highway," "Bunny's Bop") and somber, reflective ones ("The Man with the Miniature Orchestra," "Hurry into the Far Away Places"). Throughout the collection, arrangements that nod to Latin pop and chamber pop with exotic percussion, classical guitar, and harpsichords -- as well as staples like strings, piano, and brass -- reflect the eclectic directions instrumental music took in the latter half of the decade. Other highlights include the wonderfully tragicomic "At the Codfish Ball," the buzzing anticipation of "The Arrival," and the spaghetti Western drama of "Glo-Coat." While Mad Men's savvy pop song choices and iconic theme song tend to steal the musical spotlight, Carbonara's score is just as vital at conveying the show's mix of fabulous style and complicated characters.