Did the Grateful Dead play at the original Woodstock concert?

Context: Woodstock Music and Art Fair, commonly referred to as Woodstock, was a music festival held during August 15–18, 1969, on Max Yasgur's dairy farm in Bethel, New York, United States, 40 miles southwest of the town of Woodstock. Billed as "an Aquarian Exposition: 3 Days of Peace & Music" and alternatively referred to as the Woodstock Rock Festival, it attracted an audience of more than 400,000 attendees. Thirty-two acts performed outdoors despite sporadic rain. It was one of the largest music festivals held in history.

Answer: Yes, the Grateful Dead played a 1 hour and 35 minute set on Saturday, August 16 1969, that ended after a fifty-minute version of "Turn On Your Love Light".