The music of the Peanuts animated specials, the so-called "Peanuts sound," is the groove-filled modern jazz of piansit Vince Guaraldi. The composer was first hired by producer Lee Mendelson to write the musical score to a documentary on Charles Schulz. That film, A Boy Named Charlie Brown, introduced the adopted musical theme of the Peanuts gang, "Linus and Lucy," played by Guaraldi's jazz trio.

Guaraldi's music did not reach mass audiences until he was tapped to score A Charlie Brown Christmas. The response was and continues to be electrifying. The tune, Linus and Lucy, is recognized as the difinitive musical accompaniment to Peanuts. The song has a certain bounce and whimsy underscored with real sophistication and, like the strip itself, a hint of meloncholy and nostalgia.

Guaraldi's tune has been covered Jazz powerhouses Wynton Marsalis, Dave Brubeck, and David Benoit. Schulz himself even credited Guaraldi for the success of Peanuts on television: "His musical genius deserves a great deal of the credit for the success of the television specials." Guaraldi scored all of the specials until his death in 1976.