A screenshot from the Arcade Fire set at the Coachella music festival last weekend. YouTube streamed more than 60 acts from the event.

If you didn't catch YouTube's streaming Webcast of the Coachella music festival last weekend, you missed a chance to see the music world changing before your eyes.

For three days, viewers were treated to live sets by superstars like Kanye West, the Strokes, Arcade Fire, Duran Duran, and nearly 60 other artists. At any given moment, they could choose from performances on three separate stages--each of which had its own channel with multiple high quality camera angles--and all with low lag, few technical glitches, and fairly unobtrusive advertising.

In short, if you couldn't be at Coachella, this was the next best thing. And it didn't cost a dime. Or require waiting in line in scorching Southern California desert heat for a porta-potty.

Over the three days, people from all over the world took advantage of the opportunity to see what the festival was like, viewing the stream nearly 4 million times. And almost certainly, thousands of those watching decided that they have to go in person next year, even as the bands that played no doubt picked up large numbers of new fans they would never before have been able to reach.

This wasn't the first time, of course, that a major music event has been live-streamed. YouTube and other services have for some time been Webcasting live music, including last year's Coachella and shows over the last couple of years by major acts like U2 and Arcade Fire, and festivals like Bonnaroo. But this was likely the most complex and sophisticated live concert stream ever and indeed, the 2011 Coachella Webcast may be the most visceral evidence yet that the democratization of music has arrived.

"It felt so much more significant and cooler than anything like this that I've seen," said Rob Sheridan, the creative director for the Nine Inch Nails. They "really nailed it [and] I can see that this is where things are going."

Here's why. For YouTube, Coachella's organizers, the bands, and their fans, as well as the live stream's sponsor, Wrigley, the Webcast was an across-the-board win. No matter where you looked on social-media sites over the weekend, people from all corners of the globe were shouting out their enthusiasm for the festival, and there were countless tweets from people freely thanking the sponsor for making the Webcast possible and promising to go out and buy its gum. That's the kind of organic response on which paradigm shifts are built.

From a practical standpoint, the evidence of this is in the scope and scale of the Webcasts. For Justin Ward, the editor of Livemusicblog.com, it was important that the Coachella viewers got to choose from 61 bands, many of which would be in front of a worldwide audience for the first time. "Normally, when you've seen these [Webcasts] done in the past," Ward said, "it's one camera or one channel and eight [or so] bands that have some distribution partnership. [Coachella] was definitely the most significant in terms of artist choice."

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Coachella organizers did not respond to a request for comment.

But clearly, Coachella itself has seen the light. Last year, the festival was Webcast, but only one act at a time. And would-be viewers had to "like" sponsor Wrigley's Facebook fan page in order to watch the stream on the social-networking site, Ward recalled. Yet enough people watched that both Coachella and Wrigley felt like it was worth going all-in on the 2011 project. And bringing YouTube along with them.

"My hunch is that [Wrigley] felt that they got brand lift out of it," Ward said. "They've been the only repeat sponsor [of a major live-streamed event] that I've seen...The most prominent sponsor dollars [are a] repeat. The fact that they're coming back year after year is a very good sign."

That's for sure, since putting a huge festival like Coachella out to the world is not a cheap undertaking--and someone has to foot the bill.

While it's unknown how much the venture cost, it's likely that Wrigley put up mid- to high-six-figure dollars to sponsor the Webcast, estimated Andrew Hampp, a reporter who covers the music industry for Ad Age. But there's little doubt those dollars would be considered well spent inside Wrigley given the extremely positive feedback provided by viewers happily tweeting their gratitude. To an advertiser, of all things. And that's got to raise eyebrows on Madison Avenue. "I think in the last year or two, consumers are savvier about why things are sponsored," Hampp said, "and they feel more compelled to thank brands when they know something is valuable...If brands are lessening the barriers to entry, then everyone wins."

Then consider the benefit for bands. The Nine Inch Nails' Sheridan said that he was so impressed with the user experience over the weekend that "it makes me wish we were on tour right now with the band. It would be so great to put something like this together."

That's because, Sheridan said, there's major potential value is giving would-be ticket buyers a glimpse of what they'd see if they actually went to a live show. For a touring band, as most acts at Coachella are, that's priceless exposure.

In the past, Sheridan explained, the dynamics of putting a live Webcast together made doing so unrealistic. He said that it was a huge production that would offer poor quality while also being expensive--hardly a good combination. But YouTube's Coachella Webcast "was just an incredibly simple implementation," said Sheridan, "and it worked really, really well. Maybe that's a testament to [YouTube parent] Google being behind it and having the horsepower to pull it off. And...the way it worked so quickly, seamlessly, and lag free led to the [massive] social spread of it."

YouTube Live For YouTube, of course, the Coachella Webcast is just the latest in a growing stream of live offerings. Earlier this month, the service announced it would begin offering select partners the ability to easily live-stream events. And a quick perusal of the YouTube Live site shows a wide variety of content at any time, from major cricket matches to public policy symposiums to video game events and more.

The Coachella Webcast may not prove to be the most popular in YouTube's history--the 2009 U2 Rose Bowl show had 10 million global live streams and last year's Arcade Fire concert at New York's Madison Square Garden clocked 4.3 million--but Dana Vetter, the music marketing manager for YouTube's marketing program, said last weekend's effort, what with the multiple stages and channels and dozens of artists, may well have been the service's most advanced live offering to date.

Vetter suggested that this is just the beginning: with smart partners on board, it would seem like a no-brainer. "We see these festivals as these exceptional opportunities for artists to reach their fans...What's so exciting here is that it's providing that access [to content] to people all across the country and the world."

And what about the fans For those peering in on Coachella over the weekend from their computers, it was the kind of thing that makes people miss appointments and cancel plans. If you were planning on watching the Strokes in a few hours, why not settle in and watch Nas and Duran Duran in the interim "I barely switched away at all, sucked in more by the livestream than I have been in previous live experiences [going to] Coachella," said Evonne Heyning, herself a streaming media producer. "Usually, the experience [at the festival] is less compelling--it's hot and far to walk to the next stage where the music may not be as good. At home, I could switch through channels and see without the walk."

Heyning also recognized the advantages for the artists. "The bands looked great and probably sold a ton of downloads after," she said. "It would be interesting to see the spike in sales."

And then there's what this all means for the future of the music business. As Sheridan put it, scarcity is the only future left for the entertainment business, and with the collapse of CD sales, there's no longer a shortage of recorded music.

"But smart people are finding new forms of scarcity," Sheridan said. "Merchandise, limited edition releases, cool vinyl packages...and of course, experiences. An experience is the best kind of scarcity, and a concert is the best kind of music experience....The value of live music continues to be really high in our culture, and things like the Coachella Webcast really add to that cultural value. Coachella also recognized that recordings of live performances aren't a scarcity, but the event of everyone watching it in real time is. The thing that made it exciting, aside from the excellent implementation, was feeling like you were part of something as it was happening, something all your friends were talking about in real time."

Correction, Wednesday at 10:36 a.m. PT: This story initially misstated a statistic about the live stream viewership. It's been viewed 4 million times. .