Something unpredictable: Billie Joe Armstrong watches singer cover Green Day at England club

A singer covering a Green Day song at an England venue found himself performing in front of Billie Joe Armstrong himself.

The “American Idiot” rocker stopped by the Cavern Club in Liverpool, which is famous for hosting The Beatles back in the day, and caught a set by resident artist Callum McMorran, who just happened to be putting a spin on Green Day’s “Good Riddance (Time of Your Life).”

The Cavern Club posted footage of the moment on Instagram, adding in the caption, “Imagine performing a @greenday song to Billie Joe Armstrong… Well our resident @callummcmorran got to on The Cavern Club front stage.”

Armstrong has an England gig of his own coming up Jan. 15 in London, which he’s playing with his side project The Coverups.

A singer covering a Green Day song at an England venue found himself performing in front of Billie Joe Armstrong himself.

The “American Idiot” rocker stopped by the Cavern Club in Liverpool, which is famous for hosting The Beatles back in the day, and caught a set by resident artist Callum McMorran, who just happened to be putting a spin on Green Day’s “Good Riddance (Time of Your Life).”

The Cavern Club posted footage of the moment on Instagram, adding in the caption, “Imagine performing a @greenday song to Billie Joe Armstrong… Well our resident @callummcmorran got to on The Cavern Club front stage.”

Armstrong has an England gig of his own coming up Jan. 15 in London, which he’s playing with his side project The Coverups.