He kept his trombone activities a secret at first, as his circumspect religious father James Henry Fillmore (1849–1936)—a composer of gospel songs, often in collaboration with Jessie Brown Pounds[1]—believed it an uncouth and sinful instrument.

He began composing at 18, with his first published march "Hingham", named after a line of brass instruments.

After graduating from the Cincinnati Conservatory of Music, Fillmore traveled the United States as a circus bandmaster with his wife, an exotic vaudeville dancer named Mabel May Jones.

He went on, however, to prove the physician wrong, keeping an active schedule rehearsing high school bands in Florida and composing marches.

[5] His arrangement of "The Star-Spangled Banner" is performed by the Florida State University Marching Chiefs.

He published under a variety of pseudonyms, including Gus Beans, Harold Bennett, Ray Hall, Harry Hartley, Al Hayes, and Henrietta Moore.

"Harry Hartley" are all solos; cornet, trombone, and baritone that are easy grade with no triple-tonguing or cadenzas.

A musical trade journal explained matters similarly in 1928: “The Harold Bennett Group includes selections for various instruments covering a specific range and not too difficult.

Under his own name Mr. Fillmore has written many trombone solos and marches.”[7] While best known for march music and screamers, he also wrote waltzes, foxtrots, hymns, novelty numbers, and overtures.