William Allaudin Mathieu is a pianist, composer, teacher, and author. He has composed a variety of chamber and choral works, including several song settings of Jelaluddin Rumi's poetry, and made numerous solo piano recordings. He has written three books on music: The Listening Book and The Musical Life, both published by Shambhala, and Harmonic Experience: Tonal Harmony from Its Natural Origins to Its Modern Expression, published by Inner Traditions.

A Sufi Sheikh in the lineage of Hazrat Inayat Khan, Allaudin is a direct disciple of American Sufi Samuel L. Lewis, who encouraged Allaudin to found the Sufi Choir, which he directed from 1969 until 1982. He was a disciple of North Indian vocalist Pandit Pran Nath for 25 years. He studied African music with Nubian musician Hamza El Din, Jazz with William Russo, and European classical music with Easley Blackwood.

In the 1960's, Allaudin spent several years as an arranger/composer for Stan Kenton and Duke Ellington, was the musical director for the Second City Theater in Chicago (which he helped found) and the Committee Theater in San Francisco. In the 1970's, he served on the faculties of the San Francisco Conservatory of Music and Mills College. The last two decades have been devoted to composition, performance and teaching from his home in Sebastopol, California. Allaudin currently preforms with his wife, Devi Mathieu, and string player Shira Kammen in Ephemeros, a trio dedicated to the performance of early and contemporary music.