One of The Big Four turns the Big 4-0 this year and is celebrating with a number of special activities and events to honor the landmark anniversary. Formed by guitarist Scott Ian and bassist Dan Lilker in Queens, NY on July 18, 1981, Anthrax was one of the first thrash metal bands to emerge from the East Coast and quickly became regarded as a leader in the genre alongside Metallica, Slayer, and Megadeth.

Active over the past five decades, Anthrax has released 11 studio albums, been awarded multiple Gold and Platinum certifications, received six Grammy nominations, toured the world since 1984 playing thousands of shows, including headlining Madison Square Garden and playing Yankee Stadium with The Big 4. The band has built a strong reputation with fans as well as the record industry. With the lineup including Ian, bassist Frank Bello, drummer Charlie Benante, singer Joey Belladonna, and guitarist Jon Donais, the band is being feted on their 40th anniversary by a wide range of friends and music contemporaries.

Each week, on Mondays, Wednesdays, and Fridays, and wrapping on the band's official founding anniversary of July 18, Anthrax's social media accounts will offer a series of video testimonials sent in by former band members, fellow musicians, colleagues, and industry veterans sharing behind-the-scenes stories of working with the band and what Anthrax's legacy has meant all these years on. These videos will honor each album in chronological order beginning with the original release, Fistful of Metal. Go here for the full schedule, and watch Episode #23: Worship Music below. The episode talks about Joey Belladonna's return to the band, the Big 4 shows with Metallica, Slayer, and Megadeth, and the background of Worship Music.

The 11-week series will include video contributions from Chuck D, Corey Taylor, Dave Grohl, Dave Mustaine, Gary Holt, Gene Simmons, Henry Rollins, John Carpenter, Kerry King, Mike Patton, Nergal, Norman Reedus, Michael Poulsen, Rob Zombie, Robert Trujillo, Roger Miret, Darryl McDaniels (Run DMC), Slash, Tom Morello and more. There will also be video clips from former Anthrax band members Dan Lilker, Dan Spitz, John Bush, Neil Turbin, and Rob Caggiano.

The finale came with a very special Livestream performance from Anthrax on Friday, July 16, featuring a deep cuts set that will pull from the band's entire career-spanning catalog.