50k people attend concert with no live music

I know it sounds unbelievable but it's true. I saw it on T.V. Tonight. It was on CNN and hosted by Lisa Ling. It was called electronic Woodstock. It was on the original grounds of the Woodstock concert. It was a 3 day concert of all pre-recorded music played by disc jockeys. She said that 50k people attended the event.

I always thought you attended a concert for the live music. I guess not anymore.