In his mid-20s, he moved to Chicago where he played in jazz clubs and pursued studies in conducting, arranging, and orchestration, strongly influenced by the works of Maurice Ravel, Claude Debussy, Béla Bartók and Sergey Prokofiev.
[2] During that time, the Dennis Farnon Orchestra recorded numerous albums, including Magoo in Hi-Fi, over 10 episodes of Mr Magoo[3] cartoon shorts, Chet Atkins in Hollywood, Velvet Carpet – The George Shearing's Quintet, The Enchanted Woods, Songs From The Motion Picture Gigi with singers Gogi Grant and Tony Martin (American singer), and Caution!
The styles ranged from jazz, funk, drama and romantic to his personal favourite, comedy music, which more recently has appeared in The Ren and Stimpy Show and SpongeBob SquarePants.
Farnon resided for a short time in Cascais, Portugal, where he worked with various Portuguese composers-singers including Fernando Tordo, Carlos do Carmo and Sérgio Borges.
He continued to write short piano compositions right up until his death, always favouring lighthearted comical tunes to make people laugh, with titles such as The Camel with the Wooden Leg, Two Doves on a Chimneypot, Grass Valley and Friend, Ms. Penguin and Twinkletoes and Me.