Promoter Wal Bishop said when he saw Oh What A Night in Las Vegas in 2010 he was "absolutely gobsmacked".
He didn't believe the four performers in the tribute show to Frankie Valli & the Four Seasons were singing live until the a cappella number Silence is Golden proved it to be true.
It's not an uncommon reaction and the performers - writer George Solomon, choreographer Paul Holmquist, Brandon Albright and Rick Morgan - have always taken it as a great compliment to their ability to evoke the sound of hits like Big Girls Don't Cry, Sherry, Walk Like A Man and Can't Take My Eyes Off You.
Bishop brought the group to Australia last year for what was supposed to be a four-week tour but it just kept growing.
"They did 54 shows in 10 weeks," he said.
Now they're back again and will open the 2013 tour at the Queanbeyan Performing Arts Centre on Wednesday night. In the audience will be several women named Dawn, like the Four Seasons song, especially invited from the Q's mailing list for the opening night.
Solomon formed the tribute group with Holmquist and director Michael Chapman five years ago; this is the original company although there's a pool of about 40 singers who tour and perform in different locations. He said the last time they came to Australia, "We were overwhelmed by the response. People told us the audiences would be more reserved: they were not. They were very, very outgoing: screaming, standing, dancing."
He attributed their success to the fact it was "a feelgood show" that appealed to audiences of all ages, with a lot of comedy thrown in as well as the renditions of the songs.
"It's silly fun."
Holmquist said he deliberately did not watch the biographical musical Jer-sey Boys about the group because he did not want to be influenced by it in devising the choreography.
"I listen to the music and have a hook, a different hook for each number, so each one looks different from the next, even though there's only so many variations of step type."
After Australia, the group will tour New Zealand, then Canada - then keep going.
Solomon said, "We're booked tight through 2014."
As well as achieving popular success, the act has also been praised by one of the former Four Seasons, Holmquist said.
"We met Charlie Calello ... He was very complimentary and said we sang better than they did."
Oh What A Night is on at the Queanbeyan Performing Arts Centre on January 17, 18, 19, 23, 24, 25 and 26 at 8pm with 2pm shows on January 17 and 24 and 5pm shows on January 20 and 27. Tickets $56/$51 or $46 all matinee tickets. Bookings: 62856290.