John Arden "Jay" Ferguson (born May 10, 1947) is an American rock and pop musician known for his work with the bands Spirit and Jo Jo Gunne, and his 1978 solo hit "Thunder Island". His later career has been as a composer of music for television programs and films. Many people know Ferguson for composing the theme song for the American version of The Office on NBC. Childhood and early musical career Ferguson was born on May 10, 1947, in Burbank in the San Fernando Valley, California, to John Becker and Kathleen Jane Ferguson. He grew up in the Van Nuys and Canoga Park sections of Los Angeles. At 12 years old, Ferguson's parents encouraged his musical abilities with classical piano lessons. When he was 16, Ferguson's interest transferred to the banjo. Along with his brother Tom, an accomplished fiddle player, he formed a bluegrass group called The Oat Hill Stump Straddlers including Michael Fondiler and Steve Fondiler. Ferguson was also a member of local garage bands Western Union and The Red Roosters, as was Michael Fondiler. He also held part-time jobs at different points as a theater usher and an architect's assistant for his father John Ferguson, and taught piano in a music store and studied at UCLA after high school. The band Spirit Spirit was founded in the mid-1960s. Many musicians of the time cited The Beatles and their music as an influence, and Ferguson was no exception. Reuniting with longtime musician friends Randy California and California's stepfather Ed Cassidy, who, with Mark Andes and John Locke were in a band called the Red Roosters - Ferguson joined with them to form a jazz influenced rock group that was originally called Spirits Rebellious, after a Khalil Gibran passage. With the general consensus that the moniker was too long, they later shortened the name to Spirit. Ferguson was the last member to join the band and found himself in the position of lead vocalist and percussionist. Ferguson shared singing and songwriting duties with California, writing most of the songs on their first album. Spirit began playing at various nightclubs and concerts in the Los Angeles area, especially the clubs along the Sunset Strip, including Whisky a Go Go. At one of these shows, French film producer Jacques Demy saw Spirit perform and decided he wanted them in his next film. It led to a cameo role for the band