Although he is arguably best known for helping to organize the historic festival, his career included managing music icons like Billy Joel and Joe Cocker, as well as producing numerous rock concerts.
Lang grew up in Brooklyn, New York, and attended college in New York City before he became a concert promoter in the 1960s, Variety reported. The year before the flagship Woodstock festival, Lang organized an event called the Miami Pop Festival, which included artists like Jimi Hendrix and Frank Zappa.
Later, Lang, along with John Rosenman, Artie Kornfeld and John P. Roberts, conceptualized the Woodstock festival in Woodstock, New York, Variety reported.
It is estimated that 400,000 people attended the festival, which would go on to revolutionize not only music festivals but also the future of music, concerts and counterculture.
In 2019, Lang tried to stage a 50th-anniversary Woodstock music festival. The festival never took place.
Around that time, Lang was honored with the Lifetime Achievement Award from the Muhammad Ali Foundation.
He is survived by his wife, Tamara, and his five children: Shala, Lariann, Molly, Harry and Laszlo.
Kalhan Rosenblatt is a reporter covering youth and internet culture for NBC News, based in New York.