William Allaudin Mathieu (born 1937) is a composer, pianist, choir director, music teacher, and author. He began studying piano at the age of six, and began recording his music and compositions in the 1970s on his record label, Cold Mountain Music. Mathieu has composed and recorded solo piano works, chamber pieces, choral music, and song cycles, and he has written four books on music, music theory, and how to live a musical life.