Hanson performed a career-spanning, two-hour set during their June 17th birthday show, just one of two nights spent celebrating at NYC's Irving Plaza. While older tracks like monster hit "MMMBop" and "Lucy" off 1997′s Middle of Nowhere received the most screams, don't count out 2000′s "This Time Around" and current single "Get The Girl Back" � they were close contenders.

Before Hanson took the stage, tracks from their new album Anthem were played on the speakers and many in the crowd already knew all the words, though the record's official release date was the following day. The Hanson brothers � Isaac, Taylor, and Zac � told Radio.com that their latest release was aptly titled.

"The new album Anthem is a record that's kind of anthemic," Zac said. "I think what really shows through on this record is the return of the guitar. You see a lot more songs based around strong guitar riffs and big melodies that are designed to be sung along with. Not just a pop chorus you can remember but really a melody that screams for the whole audience to yell it back at you."

He wasn't lying. At the anniversary show, their fans screamed along to Anthem's opening track "Fired Up," which Isaac said includes a chorus that is literally "30 people, 100 people yelling,'Let's get fired up!'"

"You can't say that without pumping your fist," he explained.

Zac said the record is about fighting for things, explaining that their single "Get the Girl Back" is the perfect example for doing whatever it takes to get what you want.

"You have to fight for the girl," Zac explained. "You have to go get her. Don't sit on the sidelines. Hopefully that really rings true with Hanson fans. I think that's something that has always been in the Hanson fan culture: the idea of fighting for the music, fighting for the bands you love and the things you're passionate about. The Hanson culture is a culture of people who are fighting for whatever they care about."