Hanson are still in awe at collaborating with The Beach Boys star Mike Love because they learned to harmonise from listening to the Good Vibrations hitmakers as kids.

The MMMbop stars were approached about revamping their 2017 holiday tune Finally It's Christmas with Mike for his new album, Reason for the Season, and brothers Taylor, Zac, and Isaac jumped at the opportunity.

"They (label bosses) were like, 'Mike likes your song, and he'd like to sing it on the record,' and we're like, 'Well, duh!'" smiled Isaac during a joint appearance on U.S. breakfast show Today.

The project also helped to bring the siblings' careers full circle.

"The Beach Boys were the first concert we ever went to; I was like, six years old," shared Zac. "Obviously (we) love (their) vocals... (They're) icons."

"We're still pinching ourselves (over the collaboration)," he beamed.

Taylor added, "It's amazing... We learned (to harmonise) from listening to The Beach Boys and early rock and roll, and these guys did it the best."

Reworking Finally It's Christmas with Mike also granted Hanson the chance to join the veteran musician in the studio to cover one of The Beach Boys' old hits, It's OK, which was released over the summer (18).

At the time, Love told Rolling Stone: "I loved re-recording the song with Hanson. I think they brought a great energy to it. Brothers Taylor, Zac and Isaac grew up singing harmonies like my family did and they've written some great songs over the years. It was a blast working together."

"Twenty-five years ago, we were singing Beach Boys classics to an audience of a handful at our first concert," Taylor explained in a statement. "To be asked to collaborate with Mike Love, a music icon to us, was a total honor. There are few things greater than being granted mutual respect from an artist you greatly admire."