A ritual of mine is watching the Director's Cut of Woodstock every August. From the opening, showing the construction of the stage and interviews with the promoter who put it all together, to the sight of tens of thousands of young people gathering, to the mud-parties, through all the performances, from mediocre to awesome, it is a way to celebrate music, freedom, and a moment in time that can never come back.
The "headliner" - the star of the show - was to be Jimi Hendrix. He was gonna close on Sunday night with a blistering set. He was being well paid for it, too. Then, the rains came, the travel snafus, the schedule snafus, the performer snafus. The end result of all these issues was simple enough. Instead of playing in front of half a million people as the sun set on Sunday night, Jimi, and his cobbled-together group of musicians (not really a band; listening to the complete performance on CD makes you wonder why he brought them together; when he says "We're just jamming, that's all," he's right, because they had only rehearsed together once), Jimi played early on a Monday as people were streaming away from the festival. All the same, as a musician he showed why he had earned top billing, even if his band was not up to par. His set list, from old material to material he was developing for future releases ("Isabella", "I Hear My Train A-Comin'"), Hendrix made his guitar weep from the strain he put on it. He had been doing the national anthem for a while in performances, and would open his Isle of Wight Festival set (his last big performance before choking on his own puke, stupid bastard) with "God Save The Queen".
So, of all the songs that make me think, "Summer!", it's our national anthem that makes the cut.