The music for "A Charlie Brown Christmas" was composed by Vince Guaraldi. He was a jazz pianist and composer who is best known for his work on the "Peanuts" cartoons, including the iconic theme song for the show, "Linus and Lucy." Guaraldi wrote the music for the special with the intention of creating a unique and memorable soundtrack that would complement the animation and storytelling. He was successful in achieving this, as "A Charlie Brown Christmas" has become a beloved holiday classic, and its music has become synonymous with the Christmas season.