The context of his playing the Star Spangled Banner is what makes it truly legendary.

He didn't go on until 9am Monday, most of the crowd had gone back to their daily lives at that point after 4 days of Armageddon that was Woodstock, apparently the band did not know he was going to play it hence the sporadic accompaniment, then there's the Vietnam fuckin' war...

All the chaos that he includes is no accident and is a stark political statement. Those are the whistles of bombs dropping, people's cries, alarms sounding. He also throws Taps in. He tells a whole story via an instrumental.