"When You Wish upon a Star" is a popular song written by Ned Washington and Leigh Harline and introduced in the 1940 Walt Disney movie Pinocchio, where it is sung by Cliff Edwards in the character of Jiminy Cricket, over the opening credits and again in the final scene of the film. The song won the Academy Award for Best Original Song that year.

The song has – like Mickey Mouse – become an icon of The Walt Disney Company, used in the opening sequences of Walt Disney anthology television series and in multiple versions of Walt Disney Pictures' opening logos. The ships of the Disney Cruise Line, the Disney Wonder, the Disney Magic, and soon the Disney Dream, use the iconic first seven notes of the song's melody as their horn signals. Additionally, many productions at Disney theme parks – particularly fireworks shows and parades – employ the song. Beginning with 2006's Pirates of the Caribbean: Dead Man's Chest, the opening that precedes all theatrically-released Disney films uses the melody of the song.
=========================
http://en.wikipedia.org/wiki/When_You_Wish_upon_a_Star