After Berklee, Tropea recorded and toured with Eumir Deodato. Moving to New York City in 1967, he became one of the most sought after session players. In 1974, he played on Van Morrison's "Bulbs" and "Cul de Sac" included on the album Veedon Fleece and issued as the single. Tropea wrote and produced three critically acclaimed solo albums for TK Records. His first solo album Tropea, was released in 1975, followed by Short Trip to Space, and To Touch You Again. With those early recordings and other projects, Tropea formed close musical alliances with other leading New York musicians such as Warren Bernhardt, Michael Brecker, Randy Brecker, Steve Gadd, Don Grolnick, Anthony Jackson, David Sanborn, David Spinozza, and Richard Tee.
He played guitar on "Baby Now That I've Found You" recorded by Dan Schafer on Tortoise International Records, an RCA Records subsidiary released in 1977. In March 2012, this version was included on the compilation album, Perhaps...The Very Best of Dan Schafer. He has played with Billy Cobham, Eumir Deodato, Laura Nyro, Harry Chapin, Paul Simon,[3]Eric Clapton, and Dr. John.[3] Tropea has written and arranged music for film and broadcast advertising. With his frequent co-producer and friend Will Lee,[3] he released Simple Way to Say 'I Love You' , and Something Old, New, Borrowed and Blues, live performances by The Tropea Band at Mikell's in New York City. He composed the song "Tambourine",[4] which was used as the close for WABC's Eyewitness News broadcasts from 1977 to 1980.