1. "What's This?" by Danny Elfman: The opening song of the movie, sung by Jack Skellington. Available for piano, voice, and guitar.
2. "Jack's Lament" by Danny Elfman: Jack's emotional ballad, expressing his longing to experience Christmas. Available for piano and voice.
3. "Oogie Boogie's Song" by Danny Elfman: The villainous Oogie Boogie's catchy tune. Available for piano, voice, and guitar.
4. "Sally's Song" by Danny Elfman: Sally's heartfelt ballad about her desire for freedom and companionship. Available for piano and voice.
5. "Kidnap the Sandy Claws" by Danny Elfman: Jack and the residents of Halloween Town plot their plan to capture Santa Claus. Available for piano, voice, and guitar.
These sheet music pieces are usually arranged for various instruments and skill levels, from beginner to advanced. You can find them in music stores, online music retailers, or through the official Disney music website.