The crown jewel of the soundtrack is the use of the instrumental track "Tropicana" by Ratatat. I've always imagined this song being something that would play in the background of a film scene featuring some sort of an amnesiac drug addict wandering around in a train station. But then here it is, servicing Apatow's genius act breaks, the throbbing beat playing while cells generate on screen and then later as the image of the fetus pulsates on the ultrasound. Now I can't hear the song and not think about cells generating and baby's growing. It's like the song was created for this very purpose.

Apatow is on the top of the mountain right now when it comes to comedy. He is extremely funny as a writer and patient as a director and always seems to have his finger on the pulse. These are reasons why his movies are so good - why Knocked Up was so good. However, don't forget the music. The music is what made this movie.