Crowd estimates are ranging from 25,000 to 30,000 per day although the official estimates are forth coming for the Orion Music + More festival which offered great music and so much more.

This weekend, Metallica will perform 1984's Ride the Lightning and 1991's Metallica during their Orion Music + More Festival in Atlantic City. In the spirit of reviving those albums, frontman James Hetfield and lead guitarist Kirk Hammett talked about select tracks from each album. Today, they look back on their band's breakthrough from 20 years ago.

"People gotta let us run amok," said Lars Ulrich, drummer for Metallica when we interviewed him about the Orion Music + More festival he and his bandmates are putting on the weekend of June 23 in Atlantic City, New Jersey. And amok they did runÖ in the best way possible, judging from the fest's lineup. But after we got over the excitement of seeing names like Best Coast, Titus Andronicus, and Arctic Monkeys sitting next to metal stalwarts like Avenged Sevenfold and Sepultura, we got to thinking, How is this going to work? Even with four stages, organizing the groups is a tall order.

Growing up in Santa Monica, Calif., surfing was a rite of passage for Robert Trujillo, who, with a decade playing in Metallica, is the baby in the band. So the upcoming Orion Music + More festival June 23 and 24 at Bader Field offers a perfect juxtaposition between West Coast and East Coast.

If you can name it, think of it or experience it, chances are Metallica's already done it 20 years ago. Now 31 years into their existence, the most influential metal and hard rock band since Black Sabbath and Led Zeppelin set the blueprint are once again diving headfirst into a project the scope of which I'm not sure even they realized when they started out: The Orion Music + More Festival.

Also see Modest Mouse, Best Coast, Gaslight Anthem and more rock Atlantic City this weekend

By the end of the 1980s, Metallica had reached the ends of the heavy-metal thrash underground they had helped define. Steely, classic albums like 1984's "Ride the Lightning" and 1986's "Master of Puppets" redefined the velocity and virtuosity of metal while eschewing the trappings of MTV-approved "hair metal." There was nowhere to go but aboveground, which the band did with 1991's paradigm- and unit-shifting eponymous album, aka "The Black Album." Since that multi-platinum juggernaut, the band has sold out arenas, worked with orchestras, sued Napster, and had its awkward inner-workings..."

Rob Trujillo remembers the day Ozzfest and the Warped Tour collided.

Metallica is headed to Atlantic City and the Orion Music + More Festival at Bader Field. The two-day festival that begins Saturday will feature multiple live stages and a number of activation elements that reflect each of Metallicaís band membersí interests including a custom car show, surfing contest, skate ramp, cinema and more.