Almost exactly two years ago, we premiered a music video for the debut single from a 14-year-old singer named Billie Eilish. That single, “Ocean Eyes,” became a big viral hit — just last month, it was featured prominently in an episode of the great HBO show High Maintenance — and in the meantime, Eilish has continued to pick up significant buzz, most recently for some memorable performances at SXSW.

Last month, Eilish was the musical guest on an episode of The Tonight Show Starring Jimmy Fallon. And while she was there, she apparently recorded a spare, acoustic guitar-driven cover of the Strokes’ Angles track “Call Me Back,” which mostly served to showcase the smoky tones of her voice. Fallon has now shared a video of her backstage performance as a web-only exclusive, and you can watch and listen to it below.