First things first, have you seen Apple’s “Strength” commercial? If not, watch this:

The catchy song is called “Chicken Fat”. The singer is Robert Preston, perhaps best known as the star of the movie The Music Man.

Turns out, the original Chicken Fat song was created as exercise background music for school kids. Here’s the complete version of the original. Dismissed!

UPDATE: Apparently, the singer in the ad is not Robert Preston. According to the New York Times, a new version of the song was recorded for the commercial. [Hat tip to Steven Fisher]