A new documentary film will tell the story of the Grateful Dead, Allman Brothers Band, and The Band‘s legendary Summer Jam concert, which brought over 600,000 fans to Watkins Glen, NY on July 28th, 1973. The team behind the film has shared a trailer and is calling for individual equity investment through Wefunder.

The new film by director Jordan Bogdonavage (Lolla: The Story of Lollapalooza) and Academy Award-winning producer Art Horan (The Usual Suspects) will tell the story of Summer Jam from those who know it best, featuring new and archival interviews with the Allman Brothers Band’s Jaimoe and Chuck Leavell, The Band’s Robbie Robertson, Grateful Dead road manager Sam Cutler, and Allman Brothers management team member Bunky Odom. Original Summer Jam promoters Jim Koplik and Shelly Finkel also appear in the film in addition to serving as executive producers. Summer Jam At Watkins Glen – The Documentary will mark the first full-length feature devoted to the historic concert.

“Just looking down at this ocean of bodies. I’d never seen anything like that in my life,” Leavell says in the film’s trailer. “And I thought, ‘Wow, we’re going to play to these people. That’s crazy.’”

Related: Remembering The Grateful Dead, Allman Brothers, & The Band’s Summer Jam Festival

For many years, Summer Jam held the Guinness Book of World Records entry for the “largest audience at a pop festival,” surpassing Woodstock by at least an additional 100,000 people. In his book Aquarius Rising: The Rock Festival Years, author Robert Santelli estimated that one out of every 350 people living in the United States was at the Watkins Glen Grand Prix Raceway for Summer Jam. Furthermore, Santelli wrote, “considering that most of those who attended the event hailed from the Northeast, and that the average age of those present was approximately seventeen to twenty-four, close to one out of every three young people from Boston to New York was at the festival.”

The film’s Wefunder page states that production is already underway and nearing completion. Organizers are calling for investors, promising future equity and revenue share in the project. Additional perks are available for larger investments, including your name in the credits, copies of the film, VIP tickets to the New York or Los Angeles premiere, and credit as a co-executive producer.

Find full investment information here or visit the film’s website. Watch the trailer for the film below.

Summer Jam At Watkins Glen – The Documentary: Trailer