Twenty-one years ago, when Hanson released one of the earwormiest singles of the ’90s, the Jackson 5-reminiscent “MMMBop,” the song was summarily dismissed by many music snobs as a novelty hit, mere boy-band fluff. However, a new orchestral version of the perennial pop classic on String Theory — the brotherly trio’s career-retrospective double-album featuring gorgeous symphonic arrangements by Beck’s father, Oscar-winning composer/conductor David Campbell — not only puts the focus on Hanson’s impeccable popcraft and musicianship in general, but on “MMMBop’s” surprisingly dark and downright existential lyrics, which come into sharp relief when backed by Campbell’s lush strings.

“You have so many relationships in this life/Only one or two will last/You go through all the pain and strife/Then you turn your back and they’re gone so fast,” the Hansons bittersweetly harmonize. “So hold on the ones who really care/In the end they’ll be the only ones there/And when you get old and start losing your hair/Can you tell me who will still care?”

Sure, they’re all married fathers in their mid-30s now, but Isaac, Taylor, and Zac Hanson were only 16, 14, and 11, respectively, at the time of “MMMBop’s” release — and they were even younger when they wrote it. (Hanson have been a band for more than 25 years, and they actually made three local records before they ever landed a major-label deal.) Why on earth were they worried about losing their loved ones — and their hair! — when they were barely preteens?

“We had already experienced some trauma,” Zac, age 33, tells Yahoo Entertainment, referring to the many childhood sacrifices he and his older brothers made when they decided to chase their professional dreams. “We were seeing that we were outcasts.”

“We were traumatized. … We knew we were weird, and we knew we were making choices that were about the long tail,” adds 37-year-old Isaac — noting that “Weird,” another early composition that eventually appeared on Hanson’s breakthrough album, Middle of Nowhere, was also inspired by the brothers’ boyhood showbiz struggles.

“We were already having to make these decisions that were based on a love of music, a love of this craft, but also seeing that to do something you love, to pursue this thing, you have to give up other things,” says Zac, who was 8 years old when Hanson started gigging around the group’s native Tulsa, Okla. “You have to give up the crowd of friends for the future, of what could be, with not a lot of guarantees. It could just as easily have become a failure as it could be a lifestyle.”

“It’s the getting up every day, and trying, and realizing that you’re not necessarily going to get applause at the end of it. … We got turned down by pretty much every label there was,” says Taylor, 35, recalling Hanson’s demoralizing early gigs. “But the show that ultimately got us with an A&R person, that heard it and said, ‘Yeah, I want to sign it,’ that was a show that I would never hope anyone saw. It was terrible! There was like four people, watching paint dry.”

“All you have to say is: We opened for a girl singing karaoke,” Zac quips.

“Karaoke to Garth Brooks! It was on the flatbed of a truck, at a little festival,” Taylor chuckles. “The crummy show turns out to be the one where just the right person that understands gets on board and helps you take the next leap.”

Hanson performing in the 1990s. (Photo: George De Sota/Redferns) More

The struggles weren’t over for Hanson once they got that big break and signed to Mercury/PolyGram Records. Middle of Nowhere did go on to sell 10 million copies worldwide, and “MMMBop” went to No. 1 in 27 countries, earned a Grammy nomination for Record of the Year, and topped critics’ polls in the Village Voice, Rolling Stone, and Spin — but many other rockist critics were less kind. Then, shifts in the record business caused Hanson’s excellent follow-up album, This Time Around, to get lost in the shuffle, after the trio was transferred to Island Def Jam following the merging of PolyGram and Universal in 1999.