Carl Porter strode to a grassy rise overlooking the sweeping natural amphitheater where, 50 years earlier, more than 400,000 young people grooved to the sounds of their generation at a music festival billed as “An Aquarian Exposition.”

He threw his arms out, wing-like. As a gentle breeze tossed his curly gray hair, it seemed for a moment he might start spinning, like Julie Andrews on her mountaintop.

Indeed, these hills really were alive with the sound of music as the three days of Woodstock unfolded here a half-century ago. Today that music, and the spirit of one of the most raucous weekends in American history, still echoes in the hearts of those who were there, those who wish they were