Stefani, 55, aptly used a banana as a microphone. Fallon, 50, started with a kazoo and banged on a drum. The Roots also performed with child-friendly instruments and with silver pompoms in hand as a wink to the lyrics.

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, a xylophone, handheld drums, and kazoos.