After receiving classical training, Lombardi first performed and recorded with Red Norvo (1942–5) in a band which also included with Aaron Sachs, Specs Powell, Shorty Rogers and Eddie Bert,[2] and then on another recording with Joe Marsala (1945).

[1] At around that time, Lombardi also recorded with Lennie Tristano's trio with Billy Bauer (1946–47),[3] Wardell Gray, Stan Getz,[4] and Al Haig (all 1948).

[1] In the late 1940s, he also played in Barbara Carroll's trio with Chuck Wayne at New York's Downbeat Club.

[5] After leaving Goodman's band, Lombardi appeared on television in September 1951 as a member of Red Norvo's trio (substituting Charles Mingus, the trio's regular double bass player, who did not yet have a local musicians’ union card).

[1] In the 1950s, he recorded with Zoot Sims (1951), Mel Tormé (1951),[6] with Eddie Bert's band (1952–3, 1955), featuring Sal Salvador, Harry Bliss and Frank Isola[2] as well as with Tal Farlow and George Wallington.