Off to high-pitched land: Metallica's James Hetfield sings "Enter Sandman" on helium

James Hetfield turned 61 on Saturday and celebrated by imagining a world where Mickey Mouse fronted Metallica.

In a video posted to the 'Tallica Instagram, Hetfield inhales helium from a balloon and exclaims, "Happy birthday to me! Hi everybody, I'm 61!" While his voice was still high-pitched, Hetfield started singing the "off to never never land" part of "Enter Sandman."

Hetfield's voice was back to normal during Metallica's show Sunday at Gillette Stadium in Foxborough, Massachusetts, as part of their M72 world tour, which returned to North American on Aug. 2. The outing will resume Friday in Chicago.