It seems they were only including songs with lyrics. I didn't hear any instrumentals. So they didn't include instrumental movie scores. If they had, there's no way they could leave out something like the Theme from the Magnificent Seven, Pink Panther, etc...
I realize all of the songs on the list have lyrics. My question is why are some of the songs performed by characters and some just part of the soundtrack? If they include both, then they should include instrumentals from sountracks. And then you'd have to wonder why there are no John Williams songs on the list as well.
It's not like the songs were rated based on their importance or poignance to the story being told either. In such event how could they omit the closing scenes from Dr. Strangelove, or the opening to 2001 Space Odyssey? Plus I view the absence of any Beetles songs from Help or A Hard Day's Night a travesty when songs like Moon River, Windmills Of My Mind and Born To Be Wild are included.
And let's face it what about films like Woodstock, Tommy, The Wall, Purple Rain or The Song Remain The Same? Surely some of the classic songs performed in these movies merit mention.