Forty years ago, Grand Funk Railroad "had six gold albums and was flat broke," according to drummer Don Brewer.

But "We're An American Band" changed those fortunes nearly overnight.

That song, written by Brewer, was the Flint rock group's first No. 1 hit, while the album of the same name went platinum -- life-savers for a group that was battling its former manager in court and changing trends in music.

"We were struggling for our life because FM radio had changed from being underground to more of an AM hit format," recalls Brewer, 64, who's also a member of Bob Seger's Silver Bullet Band. "We were making all these major transitions, and it was like that album really symbolized a breaking out and a win, really -- we won that battle to continue and move on."

Nevertheless, "We're An American Band" remains Grand Funk's signature song and all-time biggest hit. And while it's been covered by scores of other artists -- including this year by Rob Zombie on his latest album -- Brewer says he's been largely disappointed by those renditions.

"I just wish someone would put a different slant on it," he explains. "Everybody that does it kind of takes our format and our thing and it's just a reproduction of the Grand Funk record. I've never heard anybody put a different spin on it. I love the fact everybody's doing it, but I'd like to hear somebody just take it in a whole different direction.

"That used to be a bit thing to us in the 70s; we used to take other songs and rework them. I mean, listen to what Vanilla Fudge did to those Motown hits -- I'd like to hear that with ('We're An American Band'). I'd like to hear somebody take something that's going on now and do something that's really different."

Grand Funk Railroad performs at the 2013 Chevrolet Rockin' on the Riverfront series at 7:30 p.m. Friday, July 26, behind the GM Renaissance Center in downtown Detroit. Admission is free. Visit www.facebook.com/RockinontheRiverfront.