Jan Bach was born in Forrest, Illinois in 1937. He studied at the University of Illinois in Urbana where he received the Doctor of Musical Arts degree in composition. His performing instruments are French horn and piano. His composition teachers have included Roberto Gerhard, Aaron Copland, Kenneth Gaburo, Robert Kelly, and Thea Musgrave. From 1962 to 1965 he was associate first horn in the U. S. Army Band at Fort Myer in Arlington, Virginia. Upon discharge, he taught for one year at the University of Tampa, Florida, and played in the orchestras of Tampa and St. Petersburg. Since 1966 he has taught theory and composition courses at Northern Illinois University in DeKalb. In 1978 he was selected as one of three professors receiving the Excellence in Teaching award; in 1982 he was recipient of one of the first eight prestigious Presidential Research Professorship grants instituted by the university. For six years he was Northern Illinois University's nominee for the national CASE Professor of the Year award. Although taking an early retirement in 1998, he continued to teach one course each semester at the NIU School of Music until June of 2004.

Bach has written for virtually every live medium of vocal and instrumental performance. His music has been recognized with numerous composition awards and grants since 1957 when, at the age of nineteen, he won the BMI Student Composers first prize. Other awards have included the Koussevitsky competition at Tanglewood, the Harvey Gaul composition contest, the Mannes College opera competition, the Sigma Alpha Iota choral composition award, first prize at the First International Brass Congress in Montreux, Switzerland, grants from the National Endowment for the Arts and the Illinois Arts Council, the Brown University choral composition award, first prize in the Nebraska Sinfonia chamber orchestra competition, and first prize in the New York City Opera competition. Six times his works have been recommended for a Pulitzer Prize in music.

Many works of Bach have been published by Associated, Carl Fischer, Galaxy, Boosey & Hawkes, Cimarron Music, ITEA Press, and others. Unusual for living composers, his recorded works include multiple performances on vinyl, including four recordings of his brass quintet Laudes, four of Four Two-Bit Contraptions for flute and horn, three of Rounds and Dances, four of Eisteddfod for flute, harp, and viola, five of Concert Variations for euphonium and piano, and other recordings of his brass quintets Triptych, Foliations and Lazy Blues; his work for narrator and chamber orchestra The Happy Prince; Skizzen for woodwind quintet, Quintet for Tuba and Strings, My Very First Solo for alto saxophone and electric piano, Oompah Suite for horn and tuba, and Concerto for Steelpan and Orchestra. Recordings of other works have been distributed for broadcast by NPR and the BBC.  Works (many unauthorized) are popping up on YouTube all the time.