Forbes was a music student under the tutelage of renowned musicians Edward Kilenyi and Max Steiner.
In 1951, Forbes joined the American Society of Composers, Authors, and Publishers (ASCAP).
Throughout his career, he penned a number of popular songs, including the "Appointment in Honduras" theme.
Forbe's talent and dedication to his craft earned him critical acclaim and recognition in the industry.
He was nominated for five Academy Awards for his music scoring on the films Intermezzo (1939);[1] Up in Arms (1944); Wonder Man (1945); Brewster's Millions (1945); and This Is Cinerama (1952).