In the 1960s, McCallum recorded four albums for Capitol Records with producer David Axelrod: "A Part of Me" (1966), "A Bit More of Me" (1966), "It's Happening Now!" (1967), and "McCallum" (1968). The most well known of his pieces today is "The Edge," which was sampled by Dr. Dre as the intro and riff to the track "The Next Episode."
McCallum did not sing on these records, as many television stars of the 60s did when offered recording contracts, but used the opportunity to make a different statement. As a classically trained musician, he conceived a blend of oboe, french horn, and strings with guitar and drums, and presented instrumental interpretations of hits of the day. The official arranger on the albums was H. B. Barnum, but McCallum conducted and contributed a few original compositions over the course of four LPs.