Ever since the Woodstock Music & Art Fair, held outside the town of Bethel, NY from Aug. 15-18, 1969, set the standard for multi-day concert spectacles, there have been countless rock festivals created in its image. But arguably none of these ever captured the cultural zeitgeist of its era quite like the original article.

Unless, perhaps, it was the inaugural edition of the Rock in Rio Festival, which, from Jan. 11-20, 1985, took over the “marvelous city” of Rio de Janeiro at a custom-built arena, aptly baptized the “Cidade do Rock,” or “City of Rock.” To a generation of Brazilian youths who had come of age under the oppressive shadow of a military dictatorship, this meant more than even its monumental scale, success and historic collection of musical talent would suggest. For them, Rock in Rio was literally the sound of freedom, and you could make a strong case that it’s this sound that has continued to resonate down the years, legitimizing the original spirit of a franchise that has since spun off multiple sequels well beyond the borders of Brazil.

In any case, it was hardly a coincidence that Brazil’s long-ruling military junta had finally consented to the first democratic presidential elections in 20 years, set for Jan. 15, 1985 — smack dab in the middle of the first Rock in Rio. Over the course of these cathartic 10 days, an estimated 1.5 million Brazilians (and foreign visitors) celebrated their hard-won democratic freedom in the company of some 40 domestic and international stars, ranging from local favorites like Barao Vermelho, Paralamas do Sucesso and Rita Lee, to global giants like Queen, Rod Stewart, Iron Maiden, Ozzy Osbourne and AC/DC. By the time Yes headlined the festival’s final night, daily televised broadcasts had convinced Brazilians that their immediate future was filled with promise and rock and roll.

Watch Queen at the First Rock in Rio

And yet, for the rest of the '80s, conditions for touring South America remained, at best, precarious by global standards, and only the biggest stars generally possessed the resources or wherewithal to venture south of the Equator. When they did, their tours were typically limited to playing a handful of stadium dates in only the largest cities. This eventually proved to be a major motivator for the long-awaited second edition of Rock in Rio — predictably named Rock in Rio II — which was held from Jan. 18- 27, 1991, this time inside the massive circular expanse of the world’s largest soccer stadium, the famed Maracana.

Once again, an impressive and eclectic selection of domestic and foreign stars was assembled, and while Brazil’s political and cultural backdrop at the time was nowhere near as dramatic, the sheer star power represented by the likes of Prince, Santana, INXS, Billy Idol, Faith No More and, uh, New Kids on the Block, left little to be desired.

But perhaps the biggest fireworks (both literal and figurative) flew on the festival’s so-called “Heavy Metal Night,” which featured Sepultura, Megadeth, Queensryche, Judas Priest and Guns n’ Roses. The first clash came when Brazilian pop-rocker Lobao, who was unfairly placed, got pelted off the stage by the unforgiving headbangers. The second happened when GNR (playing their first shows with new drummer Matt Sorum) were rumored to have imposed limits on Judas Priest's staging and lighting, to which Priest responded by giving one of their most famous performances.

Watch Judas Priest at Rock in Rio II

Still, by most measures, Rock in Rio II was a roaring success. Yet the brand would still lie dormant for an entire decade before it was finally revived for 2001, at the site of the first edition, where a new and improved “Cidade do Rock” was erected to accommodate as much as a quarter million people per night! This time, headliners included Sting, Neil Young, Red Hot Chili Peppers, R.E.M., the Dave Matthews Band, Foo Fighters and Iron Maiden, who recorded a live album to mark the occasion and donated its proceeds to ailing former drummer Clive Burr, who had been diagnosed with multiple sclerosis.

But perhaps the biggest headlines of Rock in Rio III were reserved for the surprise re-emergence of Guns N’ Roses -- albeit with a much different lineup -- after nearly a decade of gossip-laced seclusion on the part of front man Axl Rose.

Watch Guns N' Roses at Rock in Rio III

All this helped Rock in Rio III topple its own prior attendance records and set the stage for a subsequent geographic expansion that reflected the vanishing borders of the internet-connected global village. Indeed, in 2004, the Rock in Rio brand would cross the Atlantic Ocean for the first of multiple, biennial festivals based near Lisbon, Portugal. From a press and business standpoint, all Lisbon editions of the festival have met with great success, and while the increasing number of pop acts invited to perform had some purists grumbling that “Pop in Portugal” may have been a more apropos name than “Rock in Rio,” the fact is rockers still made their presence known by way of Metallica, Foo Fighters, Kings of Leon and Paul McCartney (in 2004), Red Hot Chili Peppers, the Darkness, Sting and, again, Guns N’ Roses (2006), and Bon Jovi, Rod Stewart and Metallica (2008).

The third of these Portuguese installments added a sister festival in Madrid, Spain, spreading concert dates between the two countries over multiple weekends, and establishing a format later duplicated in 2010 and 2012, with performances by the likes of Lenny Kravitz, the Police, Megadeth, Jane’s Addiction, Rage Against the Machine, Mastodon and Metallica. Notably, the Lisbon portion of the 2012 festival was the first in the series to adopt a multi-stage, genre-specific, lifestyle product-endorsed blueprint so popular with music festivals today. Moreover, these recent editions were among the first to experiment with interactive promotions, like allowing fans to request songs from their favorite acts ahead of time.

Meanwhile, 2011 had seen Rock in Rio revived once again in the city of its birth, for another historic rock and pop extravaganza involving nearly 100 homegrown Brazilian and international artists. By now, everything about the mega-event had become relatively familiar, from its location near the original “Cidade do Rock” (soon to be adapted into the Olympic Village for 2016’s Olympic Games in Rio de Janeiro), to the impressive collection of major names (Metallica, Elton John, Guns N’ Roses), but fans showed their unwavering enthusiasm yet again, by snapping up every ticket available in a mere four days.

Watch Metallica at Rock in Rio IV

That same enthusiasm infected Rio de Janeiro two years later, when the fifth, Brazilian-based edition of Rock in Rio significantly freshened up the franchise with an astonishing lineup of first-time performers, including Muse, Slayer, John Mayer, Living Colour, Nickelback and, most anticipated of all, Bruce Springsteen. These were joined by familiar but ever welcome faces like Metallica, Bon Jovi, and Iron Maiden, whose return brought older fans back, full circle, to that first, historic Rock in Rio way back in 1985, and its unique socio-political repercussions -- but mostly the music.

The sixth installment of Rock in Rio Lisbon began May 25, 2014, boasting everyone from Linkin Park to Queens of the Stone Age to the Rolling Stones, among other greats. Just as exciting are the recent announcements of twin follow-up festivals for 2015: one of them back home in Rio for the sixth time, and the other in Las Vegas, which will mark Rock in Rio’s American debut with the construction of a massive new venue and festival grounds on the outskirts of Sin City.

Watch the Rolling Stones at Rock in Rio Lisbon

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