Gwen Stefani, Jimmy Fallon and The Roots sang 'Hollaback Girl' on classroom instruments during the Nov. 26 episode of 'The Tonight Show Starring Jimmy Fallon.' The singer released her fourth solo studio album 'Bouquet' earlier this month.

Gwen Stefani stepped into a time machine with Jimmy Fallon and the Roots on The Tonight Show to perform her 2005 hit "Hollaback Girl." Using a banana as a microphone, The Voice host sang the foot-stomping track as Fallon and the house band shook tinsel-colored pom poms and performed with a tambourine,

Gwen Stefani's "Hollaback Girl" is a sassy spelling lesson, so it's fitting that she'd finally take it into the classroom. In a video from November 26, Stefani joined Jimmy Fallon and The Roots in the iconic Classroom Instruments setting to perform "Hollaback Girl,