Cooper's first big break came when producer H.B. Barnum chose his song "Peanut Butter" for a single by the vocal group the Marathons; the record became a nation-wide hit in 1961, and Cooper left school to pursue music full-time. While he cut a handful of novelty singles under the names Don & Marty and El Clod (as well as simply Marty Cooper), he fared better as a songwriter and producer; he was behind the controls for several sides by R&B singer Bobby Day, and frequently collaborated with noted arranger and composer Jack Nitzsche, helping to write one of Nitzsche's rare hits under his own name, "The Lonely Surfer." In 1963, Cooper arranged and produced an eccentric album for RCA under the moniker the Marty Cooper Clan; New Sounds, Old Goodies featured a vocal chorus singing the lead guitar parts to a number of instrumental rock hits, with a band of first-call session men backing them up. Cooper teamed up with another celebrated songwriter and producer, Lee Hazlewood, for his next project. The Shacklefords were a pop-oriented folk group featuring Cooper, Hazlewood, Albert Stone, and Gracia Nitzsche (Jack's wife), and they recorded an album for Mercury in 1963, Until You've Heard the Shacklefords, You Ain't Heard Nothin' Yet. A single drawn from the album, "A Stranger (In Your Town)" was a modest hit, but the group didn't record a follow-up until 1966, The Shacklefords Sing, which was issued by Capitol. A few singles on Hazlewood's LHI label appeared before the group called it quits. In 1968, Cooper produced the first album for a singer and actress known as Jennifer, titled I Can Remember Everything. The album didn't sell especially well, and neither did its follow-up, 1969's See Me, Feel Me, Touch Me, Heal Me, but in the '70s the vocalist would enjoy greater success under the name Jennifer Warnes. Warnes fared far better than another of Cooper's production clients, Catherine Share, who recorded Cooper's song "Ain't It, Baby" in 1965 under the name Charity Shayne. Share's music career soon went south, she became a member of Charles Manson's outlaw "Family," and later served five years in prison in connection with a fumbled 1971 armed robbery that led to a shootout with police.
Throughout the '60s and into the early '70s, Cooper continued to write songs that were covered by a number of major artists, including the Kingston Trio ("Little Play Soldiers"), Bobby Bare ("Cowboys and Daddys"), Stevie Wonder ("Hey Harmonica Man"), Donna Fargo ("You Can't Be a Beacon if Your Light Don't Shine"), and even Donny & Marie Osmond ("A Little Bit Country, A Little Bit Rock n' Roll"). When Cooper was introduced to producer Ken Mansfield by his friend Rick Cunha, Mansfield offered to sign Cooper to a deal with Barnaby Records, a label founded by Andy Williams that was expanding into the pop and country markets. Cooper's 1972 album, A Minute of Your Time, his first full-length release since the ill-fated New Sounds, Old Goodies, received positive reviews and spawned a minor hit single, "The Indiana Girl," but the album itself didn't make much of an impression commercially, and was Cooper's only album for Barnaby. (Williams appeared to bear no hard feelings, recording one of Cooper's songs for his 1980 album Let's Love While We Can.) In 1979, Cooper released his third album, If You Were a Singer, which was issued by EMI in Germany and other European markets, but not the United States. From this point on, Cooper put singing and producing on hold in favor of writing, and he appeared to quietly fade from the music scene. In 2012, the noted U.K. reissue label Big Beat gave Cooper's music a new lease on life with the release of the collection I Wrote a Song: The Complete 1970s Recordings. ~ Mark Deming, Rovi