I need help remembering a song...?!

Question:

I need help remembering a song...?

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I was watching a video and they played the tune that the song goes to so if someone could watch it and perhaps tell me what the actual song is I would really appreciate it.

http://www.youtube.com/watch?v=vppollyu6...

If you don't want to watch the entire video its a min and 6 seconds into it. ("Happy Birthday, Happy Birthdaaaaay")

Answers: mad world by gary jules

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