In 1959 Schmidt formed the company Avant Publishing, specializing in the publishing of classical music. In 1964, Avant became the core of Western International Music, Inc (WIM), of which Schmidt was founder and president.
Much of William Schmidt’s music was influenced by jazz and folk music. He composed and arranged music primarily for saxophone, woodwinds, brass and percussion—from solos and chamber music, to clarinet choir, brass choir, symphonic winds, band and orchestra — a total of 160 original compositions, and 470 arrangements. All but the last few compositions have been published. His works have been recorded by over 50 recording companies.
After moving to Greeley, Colorado, in 1987 Mr. Schmidt won the city’s competition for writing a trumpet fanfare to commemorate the new performance hall. In 1989 he won the Creative Fellowship in Music Composition awarded by the Colorado Council on the Arts and Humanities. In 1990 he was Composer-In-Residence at the Breckenridge Music Festival.