"Part of Your World" serves as "The Little Mermaid"'s theme song. The entire film is defined around "Part of Your World", which provides the film with momentum within its first 15 minutes. As "the heart and centre of the score," several instrumental versions of "Part of Your World" are heard throughout the film in the form of a leitmotif, overtures incorporated into its orchestral score. Although the theme belongs to Ariel, it remains "the film's most consistent thematic idea" and is thus manipulated throughout "The Little Mermaid" to various affects for other characters as well that range from melancholic to sinister. The film's main title is a choral arrangement of the ballad, performed without any lyrics. After Ariel rescues Eric and returns him to safety on a nearby beach, she sings a shorter reprise of "Part of Your World" to him as he regains consciousness. A distorted version of "Part of Your World" plays while Triton destroys Ariel's items, Eric constantly plays the melody on his flute to show that he continues to be haunted by the memory of the mysterious girl who saved his life, and a brass arrangement of the song is heard while Ursula magically transforms into a human named "Vanessa" in order to trick Eric into marrying her. Lastly, a final choral version, entitled "Happy Ending", is performed after Ariel and Eric's wedding.