Marty Callner, the 12-time Emmy nominee who created HBOs Hard Knocks and directed and/or produced music videos and TV specials featuring the likes of Cher, Garth Brooks, Robin Williams, Jerry Seinfeld and Chris Rock, has died. He was 78.

Callner died Monday at his home in Malibu, his rep Gail Parenteau announced. His son Jazz said it was from natural causes.

The first music videos he directed were ones in 1984 for Twisted Sisters Were Not Gonna Take It and Pat Benatars We Belong, and he also handled Chers If I Could Turn Back Time Aerosmiths Cryin, Crazy, Amazing, Livin on the Edge, Sweet Emotion, Dude Looks Like a Lady and Love in an Elevator Whitesnakes Here I Go Again, Poisons Every Rose Has a Thorn, Stevie Nicks Stand Back and Bon Jovis Lie to Me, more than 200 in all, most for MTV. His music/concert specials included Bette Midlers Diva Las Vegas, Benatars In Concert, Britney Spears Live From Las Vegas, Diana Ross Live at Caesars Palace, Fleetwood Macs Mirage Tour, Brooks Live From Central Park, Gladys Knights Live at the Greek Theatre, Gloria Estefans Caribbean Soul: The Atlantis Concert, Justin Timberlakes FutureSex/LoveShow, Paul Simons Live at the Tower Theatre, the Rolling Stones Four Flicks, Stevie Nicks Bella Donna and Whitney Houstons Concert for a New South Africa.

Callners Hard Knocks is considered the first sports-based TV reality series; in collaboration with NFL Films, it has taken viewers inside a teams training camp every year since 2001.

In 2022, The New York Times wrote that he might be the most successful director you have never heard of.

Callner was born in Chicago on Aug. 25, 1946, and raised in Cincinnati. His mother, Ethel Jane, got him his first job in show business as a prop man on The Nick Clooney Show. He was working in news at WCPO-TV in Cincinnati when he got his first chance to direct when someone had to leave because of a family emergency.

He helmed commercials in Cleveland and worked with the NBAs Boston Celtics through the mid-1970s until he was noticed by HBO, where his early assignments included directing Richard Harris in Camelot on Broadway and producing live Wimbledon tennis matches. (He chose the relatively new HBO over a job doing sports at NBC.)

Callner is also credited with creating the template for what is the stand-up comedy special, having directed HBOs first one, 1975s An Evening With Robert Klein, using a whopping five cameras. He then went on to helm many in the series of HBO On Location specials, including the iconic George Carlin: Live From Phoenix in 1978. (Carlin served as the best man at his wedding.)

Callner teamed with Mitzi Shore and her Comedy Store nightclub to discover up-and-coming talent to showcase on HBOs Young Comedians shows. These included the likes of Williams, Seinfeld, Billy Crystal, Howie Mandel, Mike Binder and Jim Carrey.

He also discovered Paul Ruebens at The Groundlings in Hollywood and was the driving force behind the original Pee-wee Herman Show, which was taped at the Roxy in West Hollywood to air on HBO in 1981.

He also worked with Steve Martin, Redd Foxx, John Leguizamo, Sam Kinison, Whoopi Goldberg, Whitney Cummings and George Lopez during his career.

Among his Emmy noms was one for the 2009 HBO special Youre Welcome America: A Final Night With George W. Bush, starring Will Ferrell as the 43rd president.

As the head of his production company, Cream Cheese Films, he did lots of his live music specials and concerts with longtime producing partner Randall Gladstein.

Survivors include his second wife, Aleeza, whom he married in 1981; his kids, Dax, Chad, Lin, Oriel, Jazz and Tess; and his grandkids, Chloe, River, Ben, Stevie, Ezra, Lyla, Noah and Abigail.

Marty Callner was a visionary director whose work shaped the landscape of comedy for generations, National Comedy Center executive director Journey Gunderson said in a statement.

From his iconic HBO specials with Robin Williams, George Carlin, Robert Klein, Billy Crystal, Chris Rock and Jerry Seinfeld to his groundbreaking concert films, he brought stand-up comedy to life in a way that was both intimate and unforgettable. We honor his extraordinary legacy and the joy he brought to audiences everywhere.