FOO Fighters dynamic duo Dave Grohl and Taylor Hawkins aren’t making any promises about Rick Astley’s Never Gonna Give You Up making it onto their covers list for their world tour.

The pair slipped into Sydney on Monday to spruik their upcoming new record Concrete and Gold and play an impromptu gig with their covers band Chevy Metal at the Oxford Art Factory.

Hundreds of fans queued outside the small inner-city venue after the band announced the impromptu gig on social media early on Tuesday morning.

Chevy Metal was started by Hawkins several years ago when the Fooeys were on a break.

They perform songs by Queen, David Bowie, Van Halen, Black Sabbath and from some of their other favourite bands.

media_camera Dave Grohl and Taylor Hawkins from The Foo Fighters and Chevy Metal. Picture: Richard Dobson

The much-loved rockers blew up social media when they Rickrolled the Summer Sonic festival in Japan recently by inviting Rick Astley on stage to perform his enduring pop anthem Never Gonna Give You Up.

Grohl revealed on Tuesday that the band had been jamming on the song in the warm-up room before their set when they saw Astley was also on the festival bill.

After a few runs of the song, they suddenly realised it shared a similar arrangement to Nirvana’s Smells Like Teen Spirit and later performed a mash-up of the two chart-topping hits with Astley joining them on stage.

The band famously blasted the song at controversial Westboro Baptist Church members who protested outside a Foo Fighters concert in Kansas City two years ago.

Foo Fighters invited Rick Astley onstage in Japan to perform a mash-up of Never Gonna Give You Up and Smells Like Teen Spirit.

“We will never forget that song now. Once we started jamming it backstage, we kept Rickrolling ourselves all day long,” Grohl said.

“We were cracking up when we realised it had the same arrangement as Smells Like Teen Spirit. We didn’t know if we were going to do it or not.

“Halfway through the gig, I see standing at the side of the stage and I walked over to him in the middle of a keyboard solo and say ‘Hi, I’m Dave’ and he says “Hi, I’m Rick’, I walked back over to the guys and said ‘We’ve gotta do it.’”

The band’s first studio record in three years, concrete and Gold is released on September 15 and features a surprising cast of special guests including Grohl’s friend Paul McCartney, Boyz II Men’s Shawn Stockman, who he met in a studio carpark, and The Kills’ Alison Mosshart.

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media_camera Foo Fighters will tour Australia next year. Picture: AFP

There is also a secret superstar — “probably the biggest pop star in the world”, according to Grohl, who contributes backing vocals on one of the songs.

While many people have speculated it is a female pop artist, with Lady Gaga, Adele and Taylor Swift thrown into the rumour mill, Grohl let slip in Sydney that the secret backing singer is a “he”. So perhaps it is Justin Timberlake or the other Justin, Bieber.

After teasing fans with their Chevy Metal gig on Tuesday, the entire Foo Fighters band will return to Australia to tour next year.

Originally published as Grohl spills Foo Fighters’ secrets