A native of Waseca, Minnesota, Shield was an employee of RCA Victor's National Broadcasting Company, for which he composed and conducted on-air musical pieces. Starting approximately 1922 (seven years before the Victor Talking Machine was bought by RCA and became RCA Victor), Shield was a Victor house musician, conducting and providing piano accompaniment on many hundreds of popular and USF (foreign language and ethnic recordings for issue in the United States) Victor recordings. He also worked as a part-time employee for the Hal Roach film studio, composing countless background themes that became associated with such Roach comedy series as Laurel and Hardy, Our Gang, ZaSu Pitts and Thelma Todd, and Charley Chase. One of his compositions for the 1930 Our Gang 1930 short Teacher's Pet, "Good Old Days," became the theme song of the series. His 1930 song "Beautiful Lady" was used as the theme song for the Pitts and Todd films.
Due to a series of miscommunications, Shield's requests for scoring assignments from the Roach organization were repeatedly declined after 1936, going instead to Marvin Hatley. Shield continued to work for NBC in various musical capacities, including composition and conducting. He also authored two tone poems (Glouchester and The Great Bell) and the classical Union Pacific Suite.
In 1992, the Dutch musical group The Beau Hunks (named after the Laurel and Hardy film) transcribed and recorded compositions by Shield. These recordings drew praise from cartoonist R. Crumb (who rendered a portrait of Shield for the CD cover). These recordings led to a renewed appreciation of the composer's work.