In December 2011, Dave Mustaine of Megadeth joined Metallica on stage at their 30th-anniversary concert in San Fransisco at The Fillmore. Mustaine, who was an original member of Metallica before he was famously fired, joined the band on stage for several songs including "Seek and Destroy," "Metal Militia," "Phantom Lord" "Jump In The Fire" and "Hit the Lights."

Anthrax's Joey Belladonna and Drowning Pool collaborated on the high seas while onboard the Shiprocked cruise. The rockers performed on Jan. 24, 2022, and covered DIO's classic hit, "Holy Diver."

BABYMETAL teamed up with Rob Halford to collaborate on not one but two songs at the 2016 APMAs. They broke out "Painkiller" and "Breaking The Law" to create a widely approved mashup.

Falling In Reverse covered "Gangsta's Paradise" for Punk Goes 90s Vol. 2. The band surprised fans at the 2014 APMAs with a performance of the song featuring the track's originator, Coolio, along with former Issues frontman Tyler Carter. A collaboration that most people didn't know we needed.

What do you get when you bring together Dave Grohl, Slash and Lemmy Kilmister? An epic rendition of "Ace of Spades." The trio performed the hit in 2010 during the Revolver Golden Gods Awards where Kilmister was receiving the Lifetime Achievement award.

The year is 2006 and The 48th Annual Grammys brought together Linkin Park, Jay-Z and Paul McCartney to do a mashup of each of their greatest hits. What came out of it was an epic performance of "Numb," "Encore" and "Yesterday" that no one would soon forget.

Wagakki Band invited Evanescence‘s Amy Lee for a special concert called the “Premium Symphonic Night Vol.2” at the Osaka-Jo Hall in Japan in February 2020. The band and Lee previously collaborated on their single "Sakura Rising." To the delight of fans, they released footage of them dueting and performing a rendition of "Bring Me to Life" on their YouTube channel.

Who could forget the 2017 Grammys when Lady Gaga and Metallica collaborated? The unlikely pairing created a one-of-a-kind spectacle and stage production despite the disastrous technical fails. First, the presenter forgot to announce Metallica. If that wasn't bad, someone forgot to turn on James Hetfield's microphone, causing Gaga and Hetfield to share a singular microphone. Despite the flubs, they released rehearsal footage that showed how their performance should have taken place.

Woodstock 1999 featured a performance of Creed alongside The Doors member Robby Krieger. The band played the second to last set on the final night of the festival and surprised fans with their special guest for a rocking rendition of "Roadhouse Blues."

In honor of Sepultura's 30th anniversary, they performed an unforgettable set at Rock In Rio in 2015. Steve Vai came out to jam with the band around the 40-minute mark of their live stream. Not only was it epic, but this worked out perfectly as they haven't had two guitarists since 1996 when Max Cavalera departed.