Billie Joe Armstrong Watches Green Day Cover at Liverpool Cavern Club

Billie Joe Armstrong dropped by the famous Cavern Club in Liverpool on January 7. During his visit, house musician Callum McMorran played "Good Riddance (Time Of Your Life)" - not realizing the song's creator was just a few feet away recording the performance.

McMorran has been playing at the club since 2008. His performances feature hits from The Who to Stevie Wonder, breathing new energy into familiar tunes. He previously tried for fame on The Voice UK back in 2015.

The song McMorran chose that day was first released on Nimrod, Green Day's fifth album. Though Armstrong had actually written it years before it made it onto the record.

The Cavern Club is located on Matthew Street, where The Beatles got their start playing nearly 300 shows in the early 1960s. The brick walls have witnessed countless moments of music history.

Armstrong also visited Strawberry Field while in Liverpool, which was the place that inspired the Beatles classic "Strawberry Fields Forever."

Armstrong's visit to the Cavern Club came just days before his other band, The Coverups, was set to play London's O2 Islington Academy on January 15. Green Day's Mike Dirnt joins him in that side project.