This came as a bit of a surprise over the weekend: guitarist Rob Caggiano has quit Anthrax. He's been their lead guitarist since 2001 (aside from a short break while Dan Spitz returned for a mid-noughties reunion of the Among The Living line-up) and has appeared on two of the band's albums, including the critically acclaimed Worship Music. "I'm Alive" from Worship Music has been nominated for the Best Hard Rock/Metal Performance Grammy alongside Halestorm, Iron Maiden, Megadeth, Lamb of God and Marilyn Manson.

Caggiano says: "This is an extremely difficult and emotional decision for me to make but my heart is just steering me in a different direction right now. I’ve always been one to follow my heart in everything that I do and while this might be one of the hardest decisions I have ever had to make, it feels like the right one for me at this time. Scott, Charlie, Joey, Frankie (and John Bush) will always be part of my family and this decision doesn’t change the way I feel about that in the slightest."

Anthrax released this statement: “Rob has been an integral part of Anthrax for so many years, as our lead guitarist, in a production capacity, but most of all, as our close friend. His contributions to the band have been enormous. While we are sad that he is leaving, we wish him nothing but great success going forward, and hope to share the stage with him again sometime down the road."

So where to from here? Well judging by his Twitter stream, Dan Spitz seems to either be hinting that he's back, or is gunning pretty hard for the job. He's re-tweeted dozens of fan messages calling for his return. Virtuoso shredder Rusty Cooley is also keen for the job, tweeting to anyone and everyone connected with the band to ask how to lock down an audition.