The stage times at Woodstock were a little unusual. You're probably used to the headline act of a festival closing a main stage performance somewhere between midnight and 1am. Woodstock had no time for such petty concerns. They had acts to fit in, and they were going to use all the time available to them. That meant major acts starting their sets at pretty crazy times of day. Janis Joplin, for example, didn't even start her Saturday set until 2am. Fortunately, nobody at Woodstock ever wanted to go to sleep.
Joplin tore up the stage with a legendary performance, playing a ten-song set that drove the crowd into a frenzy and finishing with her classic 'Ball and Chain'. This photo captures her in her element, clearly enjoying her time to shine. Tragically just one year later she was dead, as her years of drug and alcohol excess caught up with her.