The band is shown playing a Love-in in 1967. The PA system is a modern style that didn't exist at the time. Wedge monitor speakers were virtually non-existent. The Shure SM-58 microphone hadn't been introduced yet, though similar Shure microphones were in common usage. Marshall amplifiers were quite rare, expensive and hard to get. A band like Sweetwater would have used Fender, Vox or Standell amps. The microphones used at Woodstock were Shure SM 56 models, not the SM 58 models used in the film.