Born into a cultured but not unusually musical family, Fauré revealed his talent when he was a small boy. He was sent to a music college in Paris, where he was trained to be a church organist and choirmaster. Among his teachers was Camille Saint- Saëns, who became a life-long friend. In his early years, Fauré earned a modest living as an organist and teacher, leaving him little time for composition. When he became successful, holding the important posts of organist of the Église de la Madeleine and head of the Paris Conservatoire, he still lacked time for composing, retreating to the countryside in the summer holidays to concentrate on composition.

By his last years, Fauré was recognised in France as the leading French composer of his day. An unprecedented national musical tribute was held for him in Paris in 1922 headed by the President of the Republic. Fauré had many admirers in England, but his music, though known in other countries, took many decades more to become widely accepted. His music has been described as linking the end of Romanticism with the modernism of the second quarter of the 20th century. When he was born, Hector Berlioz was still composing, and by the time of his death the atonal music of the Second Viennese School was being heard. The Grove Dictionary of Music and Musicians, which describes him as the most advanced composer of his generation in France, notes that his harmonic and melodic innovations affected the teaching of harmony for later generations. In contrast with the charm of his earlier music, his last works, written when increasing deafness had struck him, are elusive and withdrawn in character.

In 1974, Sauer was named Principal Trombonist of the Los Angeles Philharmonic by Zubin Mehta. He made his Los Angeles Philharmonic concerto debut in 1979, performing Kazimierz Serocki's Concerto for Trombone and Orchestra with Zubin Mehta conducting - a work whose U.S. premiere Sauer gave at the Eastman School of Music in 1965. In March 2003, Sauer premiered Augusta Read Thomas’s Trombone Concerto with the Los Angeles Philharmonic, conducted by Esa-Pekka Salonen. He was also a frequent performer with the Philharmonic's New Music Group. He retired from the orchestra in 2006.

Sauer has appeared as soloist with many orchestras and has given master classes and recitals throughout Europe, Scandinavia, Japan, Mexico, Costa Rica, Canada, and the United States. He has appeared at the Stratford, Marlboro, and Aspen summer music festivals and was visiting professor at the Eastman School of Music as well as an instructor with the New World Symphony (Miami) and the International Brass Festival in Melbourne (Australia). Currently, Sauer is on the faculty of Music Academy of the West and Arizona State University. He has taught many prominent trombonists, including Christian Lindberg.

Sauer is a founding member of Summit Brass, and is a clinician for Shires trombones.

He is featured on a number of recordings, including:
A recording of works by Teleman, Handel, Haydn, and others (with Zita Carno on keyboards) (Crystal Records)
The Mahler Symphony No. 3 , with Esa-Pekka Salonen conducting the Los Angeles Philharmonic (with Anna Larsson, contralto; Donald Green, posthorn; Martin Chalifour, violin; Paulist Boy Choristers of California, Women of the Los Angeles Master Chorale) (Sony Classical)

Two discs of orchestral excerpts for trombone with commentary (Summit Records, OrchestraPro series). These are among the most sought after discs for those preparing for orchestral trombone auditions.