A bill of diverse acts, tasty food and beverage options, warm temperatures, the smell of summer in the air, and a sea of fellow festivalgoers — these are some of the essential ingredients of the summer music festival season.

As the music industry dives into another bustling summer festival season, it looks to be a winning one. Despite the still-dormant economy and soaring gas prices, young and veteran fans alike are flocking to festivals in droves.

"If I wasn't playing these festivals, I'd be at them anyway," says Wayne Coyne, frontman of the Flaming Lips, who are once again active on this summer's circuit having played the Sasquatch! Music Festival in George, Wash., on May 29.

"Trying to beat the heat when you've been awake until 6 o'clock in the morning and [trying] to sleep in your tent [as] the sun comes up. I think that's the part I like about [festivals] the most."

There are myriad reasons why festivals are rocking while other live music options might be sagging. This year's installment of the Bonnaroo Music & Arts Festival, which kicked off June 9 in Manchester, Tenn., marks the festival's 10th anniversary. With four days, 12 stages and approximately 200 acts, the festival has been sold out since mid-May.

"It's actually a value proposition to see a festival," says Rick Farman, co-founder of production company Superfly Presents, co-creators of Bonnaroo. "For $250, plus whatever it costs you to get there, you can see a volume of music that would cost you thousands and thousands of dollars if you were going to regular concerts. And it's more than that. There a lot of [other] entertainment options [at a festival].

"In this day and age, people are looking for immersive, interesting experiences. When you live at the festival for three or four days you get a really deep, different experience than what's going on in most peoples' lives on a daily basis."

Summer festivals have big drawing power, with Bonnaroo and Texas' Austin City Limits Music Festival drawing upward of 75,000 attendees in 2010, and the 2011 installment of the Coachella Valley Music and Arts Festival in Indio, Calif., totaling more than 225,000 attendees.

Of course, the bands are the main attraction. Just taking a quick look at the headlining and supporting talent for some of this year's major summer festivals reveals a breadth across many genres.

Bonnaroo will showcase a diverse lineup of artists from GRAMMY winners Arcade Fire, the Black Keys, Eminem, Lil Wayne, Loretta Lynn, Neil Young and 53rd GRAMMY nominees Mumford & Sons to non-mainstream artists such as Aunt Martha, Bassnectar, Cristina Black, DJ Logic, School Of Seven Bells, Twin Shadow, and a lot more in between.

Lollapalooza will also celebrate an anniversary, its 20th, in grand style Aug. 5–7 with GRAMMY winners Foo Fighters, Coldplay, Cee Lo Green, and Muse, as well as Skylar Grey, My Morning Jacket, the Pretty Reckless, and Ryan Bingham & The Dead Horses, among others.

According to Lisa Hickey, marketing director for C3 Presents, the production company for Lollapalooza and the ACL Music Festival, festivals offer fans a lot to discover.

"The overarching theme of any festival is musical discovery," says Hickey. "You will have headliners and more well-known acts, but most people are going to check out new music and hopefully discover a new favorite band. You go to a festival because you're excited about 10 bands. But you might see 10 more that you probably wouldn't have seen otherwise."

And with festivals, there is always the chance that fans will experience something different, and possibly historic. Think Jimi Hendrix's now-legendary instrumental version of "The Star-Spangled Banner" at the 1969 Woodstock festival.

"Most bands perform a different set at a festival than they would in a club," adds Hickey. "Phoenix comes to mind — when they played the ACL Festival in 2009, it was a record crowd for them. At Lollapalooza 2010, I've heard it [went] down as one of their most memorable performances ever. Bands give back what the audience gives them in terms of energy, and that's really special."

The ACL Music Festival, slated for Sept. 16–18 in Austin, Texas, has only single-day tickets available for the festival's final day. The lineup will feature more than 130 acts with everything from American Roots and bluegrass (Alison Krauss & Union Station) Americana/folk (Ray LaMontagne) and R&B (Stevie Wonder) to indie rock (the Airborne Toxic Event), singer/songwriters (Brandi Carlile), and hip-hop (Kanye West).

Other upcoming summer festivals include Summerfest (June 29–July 3, July 5–10, Milwaukee), Pitchfork Music Festival (July 15–17, Chicago), the Outside Lands Music and Arts Festival (Aug. 12–14, San Francisco), and Sunset Strip Music Festival (Aug. 18–20, Los Angeles), to name a few.

"The festival model really speaks to the way the world has evolved," says Farman. "Access to music is very wide and very easy to get these days. Because people are spending so much time behind the desk at a computer, the opportunity to sample lots of types of music in an environment that's free and immersive is a no-brainer."

But even though we might be living in the age of the "modern" festival, these multiact, multiday bonanzas have something in common. They are rooted in the spirit of a community event built on the tenets of harmonious coexistence through music and art — a concept that goes back decades.

As Grateful Dead guitarist Bob Weir said at Bonnaroo in 2007 while reminiscing of his days as a festival artist — and attendee — that's really what festivals are all about.

"I got a much better taste for it because I was living in the campground, I was getting rained on, I was getting muddy, all that kind of stuff," Weir said.

"But it's kind of wonderful to look back and see what's grown out of it."

(Matt Sycamore is a Pacific Northwest-based freelance music writer.)