Song question Disney song that I can't find.?

Hi! There is this song I have heard at Disneyland in CA several times at night a little bit before the fireworks. I really like the song but I can't remember the lyrics, the song name, only the tune. It doesn't sound like one of those goofy funny character songs from those movies. It sounds like a adult girl singing seriously. It's something like hum a dee dee dee dee hum dee dee dee dee. They play it at night usually around where you see Fantasia/fireworks. Please reply. Thanks!