The Will It Blend? Theme Song is the official theme song of Will It Blend?. It has appeared in every episode.
The theme is entitled "Pete's Party." It was composed by Peter Fenn (1931-2011), musical director of UK broadcaster Anglia Television. He was famous for writing themes to popular TV game shows.
The theme: https://www.youtube.com/watch?v=AwoV7-VRXcQ