Though Metallica's Kirk Hammett has shown a knack for being quite prolific, building a major catalog of riffs for previous records, he's not resting on his laurels. The guitarist posted on social media that he's using the current downtime from coronavirus isolation to work on some new riffs.

"Things are most definitely not business-as-usual, but I’m good, staying safe, working on riffs ... hope you are all okay out there as well," says Hammett, while displaying a quick-hitting clip of his fretwork.

Metallica have been off the road since last fall, when it was revealed that singer James Hetfield was entering rehab for addiction treatment. The band initially announced plans to play two headline sets at five Danny Wimmer Presents festivals, but recently had to back out of Sonic Temple and this fall's Louder Than Life due to conflicts with Hetfield's continued treatment. They are still scheduled for Welcome to Rockville, Epicenter and this fall's Aftershock Festival.

Hammett has kept active during the break, performing with the all-star Wedding Band covers group and recently appearing at a Peter Green tribute show.

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