Fillmore Wellington Ohman received his instruction in music from Edward F. Laubin, with whom he studied piano for four years, developing a remarkable technical proficiency and acquiring a thorough grounding in classical music.

After leaving high school, Ohman was detained in New York by a heavy snow storm that disrupted railway traffic. He wandered into Wanamakers' department store and tried out a piano - and was engaged on the spot as a piano demonstrator. He joined QRS in 1919 and also toured as accompanist to concert singers, and worked as an assistant organist in New York City

Ohman met Lewis J. Fuiks (Victor Arden) at QRS and they formed a hugely successful piano duo, making rolls, recordings, playing in several George Gershwin musicals, and performing on their own radio show.

Ohman's brother Ernest recalls "Phil sketched out the arrangements, but didn’t write them down. He decided the style. In their duets, Phil played the treble.” One critic at that time reported that "Arden was "the serious minded, painstaking musician", while Ohman was the "wag and clown of the pair". As an example, the critic noted "Ohman's sense of musical humour, famous among those who know him, expressed itself in his jazzing of a refrain of a negro spiritual while accompanying a singer at a staid musical concert, to the immense delight of a very proper audience."

After the duo split up in 1934, Ohman formed his own orchestra and worked in the Hollywood area until 1946. While in Hollywood, he worked in the studios, usually off-camera, for films that required an actor to simulate piano playing, as in 'The Story of Vernon and Irene Castle' (1939). He also scored and even wrote some songs for films. Probably his best known song was "Lost" (1936), with a Johnny Mercer Lyric. Along with some radio work, he remained active into the 1950's until his death.