One of the great long movies of all time, Michael Wadleigh’s culturally important four hour epic dissects the three day music festival in upstate New York and comes out, after miles and miles of edited footage, with a time capsule of an era, now bygone, of a country, a political battleground, and a sound, that is as thrilling to watch today, 40 years later, than it was, I’m sure, in the present.

What Wadleigh and his five camera-men, and Martin Scorsese and his team of crack editors, capture is a throng of people (hippies, musicians, volunteers, townspeople, financial backers), totally in sync with their surroundings and message (be it peace, love, anti-war, what have you), and not letting a potential disaster in the making (the rain, the mud, the electricity, the clogged highway) ruin what is essential, the gathering for a good time, and some really great music.

Of the music that makes the cut (and the 18 bonus tracks included in the loaded Blu-ray 40th anniversary edition), the best remains Jimi Hendrix and his nearly 20-minute medley of “Voodoo Child”, “The Star Spangled Banner”, and “Purple Haze”, which is a stunning fit of guitarmanship, but Joe Cocker’s “With a Little Help from My Friends” is just as iconic and powerful.

But who are we kidding, it’s all great, and this is one of the essential American films.