Michael Lang, organizer and co-creator of the legendary 1969 Woodstock Music and Art Fair, died on Saturday (January 8) at Sloan Kettering hospital in New York City, Rolling Stone and Variety report. Michael Pagnotta, a longtime family friend and representative for Lang, confirmed the news to both publications, stating that the cause of death was a rare form of non-Hodgkin’s lymphoma. Lang was 77 years old.

Lang was born in Brooklyn in 1944. He attended New York University briefly before dropping out and heading to Coconut Grove, Florida, where he opened a head shop around 1967. The year after, Lang and Richard O’Barry helmed promotion for the Miami Pop Festival, which featured performances from the Jimi Hendrix Experience, Chuck Berry, Frank Zappa’s group the Mothers of Invention, John Lee Hooker, and others. The event drew 25,000 attendees—a fraction of the crowds that would pour into Woodstock the following summer.

Lang was only 24 years old when he envisioned Woodstock alongside co-founders Artie Kornfeld, John Rosenman, and John P. Roberts. The four-day festival took place August 15-18, 1969 on a 600-acre dairy farm in upstate New York owned by Max Yasgur. Roughly 400,000 people attended, a rush that caused a massive traffic jam and eventually shut down the New York State Thruway.

The Woodstock lineup was packed with 1960s icons: the Who, Janis Joplin, Joan Baez, the Grateful Dead, Jimi Hendrix (whose solo performance of “The Star-Spangled Banner” became legendary in its own right), Jefferson Airplane, Creedence Clearwater Revival, and many more. Carlos Santana’s blistering set was fueled by psychedelics, which were readily available at the festival. The performance was a breakthrough for Santana, becoming one of Woodstock’s most memorable onstage moments.

Lang revived the Woodstock moniker in 1994, with 25th anniversary concerts that included performances from Woodstock ’69 alumni Carlos Santana, Crosby, Stills, and Nash, Joe Cocker, as well as bands like the Cranberries, Nine Inch Nails, Green Day, Primus, and Red Hot Chili Peppers. Woodstock ’94 was held in Saugerties, New York, roughly 70 miles from the original site in Bethel. The event would later be known as “Mudstock” after rainstorms drenched the second and third days of the festival. The mud covered audience members and artists alike. The subsequent Woodstock ’99 was more ill-fated, with a host of issues such as water scarcity, overcrowding, and other dilemmas recapped in a recent HBO documentary on the event.

In early 2019, Lang announced a festival to celebrate the 50th anniversary of Woodstock. Woodstock 50 was originally slated to take place from August 16-18 in Watkins Glen, New York. A star-studded lineup was revealed shortly after, with scheduled sets from JAY-Z, Dead & Co., Chance the Rapper, the Black Keys, Sturgill Simpson, the Raconteurs, the Killers, Run the Jewels, Janelle Monáe, Santana, Earl Sweatshirt, and more. Unfortunately, a string of setbacks followed, including issues acquiring proper permits, exiting investors and artists, a venue change, and eventual cancellation in July, 2019.

In addition to his work as a promoter and concert organizer, Lang owned and operated Just Sunshine Records, a label that released works by Karen Dalton, Betty Davis, and Mississippi Fred McDowell, among others. He also worked as an artist manager for Ricky Lee Jones, Joe Cocker, and others. Lang’s 2009 book The Road to Woodstock chronicled his journey from Bensonhurst Brooklyn, to the Miami Pop Festival, and eventually that pivotal weekend in 1969, which is still remembered as one of the most important events in rock history.