An old favourite

I have been watching videos of this performance since 1970 but did not know the background. From Rolling Stone:
"[Richie] Havens wasn't supposed to be the first act to open the festival; that slot originally was intended for the band Sweetwater, but that band wound up being stuck in traffic. Backstage, co-organizer Michael Lang approached Havens and practically begged him to go on instead. "It had to be Richie – I knew he could handle it," Lang later wrote.

After performing a half-dozen songs, Havens ran out of material – until, he later said, he remembered "that word I kept hearing while I looked over the crowd in my first moments onstage. The word was: freedom." Havens began chanting that word over and over, backed by his second guitarist and conga player, and eventually segued into the gospel song "Sometimes I Feel Like a Motherless Child," which he had heard in church as a child. The combined, surging medley wasn't just a crowd-pleaser; it later became a highlight of the Woodstock movie, which also immortalized Havens' orange dashiki. (What many didn't know at the time was that Havens wore dentures, which also gave his singing voice a unique tone.) "My fondest memory was realizing that I was seeing something I never thought I'd ever see in my lifetime – an assemblage of such numbers of people who had the same spirit and consciousness," he later recalled of Woodstock to Rolling Stone."