Music festivals have been known to be the best place for artists to make big comebacks and to debut new material. And the first day of the Governors Ball Music Festival on Randall's Island in New York City was no exception.

With so many acts on the lineup and summer perfect weather, it was a great way to not only kick off the weekend, but also get to see a number of performers that have been out of the limelight for some time.

Even though Phoenix weren't the day's headliners, their hordes of fans gathered around the main stage would make you think otherwise. Stretching from the front of the stage and spanning over what looked like a third of the island, the crowd was so massive that even frontman Thomas Mars seemed to be taken aback.

"I think this is the biggest crowd we played in New York City," he announced. "So thank you."

The band delivered many of its favorites, including 'Listomania,' 'Lasso,' '1901,' 'Entertainment' and 'Trying to Be Cool.' But one particular song sparked excitement throughout the crowd, and it was an old one. "This is the first song we ever wrote," Mars explained before the band played 'If I Ever Feel Better' off its 2000 debut LP, 'United.' "It's a little disco, so you can dance if you like."

Phoenix wasn't the only act on the bill to inspire that kind of enthusiasm. La Roux's stage wasn't as big as Phoenix's, but the British electro-pop artist packed the Gotham Tent with fans who were ready to dance.

She performed fan favorites like 'Fascination,' 'I'm Not Your Toy' and 'Bulletproof,' but it was a brand new song, 'Kiss and Not Tell' (from her upcoming album, 'Trouble in Paradise') that got the audience worked up.

In recent interviews, she's mentioned that the new album will be much sexier than her last effort, and she proved it during her performance. It wasn't that she was wearing anything too revealing, but she exuded more confidence onstage. She was unstoppable.

Jenny Lewis also gave fans a special treat on the Honda Stage. Not only was she wearing the same colorful pantsuit that she sports on the cover of her new single, 'Just One of the Guys' (which was produced by Beck), she also shared another new song from her upcoming album, 'The Voyager.'

"This next song is the first song on my new record," she said, getting comfy at the keyboard. "It's called 'Head Under Water.'" The track sounded like a mix of '80s dance pop and Lewis' signature singer-songwriter pop sounds.

Governors Ball also invited a number of newer acts to the stage, including HAERTS, Little Daylight and U.K. breakout Bastille, who were not only grateful for the chance to play the fest but also amazed at how everyone in the crowd knew just about every word to most of the songs off their debut LP, 'All This Bad Blood.'

The night's two headliners -- Outkast and Damon Albarn -- were situated on opposite sides of Randall's Island, and their sets were both packed with eager fans.

Outkast relived many of their big hits by bringing out Killer Mike and Sleepy Brown; Albarn took a similar approach, taking breaks from showcasing his new solo LP, 'Everyday Robots,' to perform Gorillaz's 'Feel Good Inc.' with guests De La Soul. By the time he got to 'Clint Eastwood,' the crowd was absolutely crazy.

What a great start to the three-day fest.

More From Diffuser.fm