In the mid-1970s, Horn worked for a music publishers on Denmark Street in London, producing demos which sometimes had Horn in charge of producing a master if a deal for a demo was made. From 1977 to 1979, Horn worked on various singles either as a songwriter, producer, or orchestra director, "without ever making any money out of it". Among his first was "Natural Dance" by Tony Cole and "Don't Come Back" by Fallen Angel and the T.C. Band, featuring Woolley as songwriter, which Horn produced under the name "T.C. Horn". He wrote "Boot Boot Woman", the B-side to the Boogatti single "Come Back Marianne", under his real name. In 1978, Horn wrote, sang, and produced "Caribbean Air Control" under the pseudonym Big A, which features Horn pictured as a pilot on the front sleeve. In 1979, a full studio album by Chromium, a "sci-fi disco project" named "Star to Star" was released that featured Horn and Downes as songwriters and producers, and Horn's future Art of Noise bandmate Anne Dudley on keyboards. Other artists that Horn worked with included Woolley, John Howard, Dusty Springfield ("Baby Blue") and The Jags ("Back of My Hand"). Horn scored his first production hit when "Monkey Chop" by Dan-I reached No. 17 on the UK singles chart in 1979.