This year marks the 20th anniversary of the formation of one of Australia's biggest-selling entertainment acts. The group in question has sold a mountain of records and DVDs (30m units and counting at the last estimate) over the past two decades, enjoying commercial and critical success all over the world. Today, this band claims to perform to more than a million fans every year.
Can you tell who it is yet? Let me introduce to you The Wiggles, the world's biggest preschool band.
Late last week, Australia's modern-day fab four announced they will shortly return to these shores - they played a storming series of concerts in Dubai last summer - for what promise to be four sell-out gigs on Abu Dhabi's Yas Island next month.
It's not hard to work out the band's appeal to both young children and stressed-out parents. The Wiggles mix catchy, feel-good tunes, brightly-coloured clothing and wholesome lyrics - in 2008, the group recorded Wash Your Hands, a song for Unicef to raise awareness of the importance of good hygiene in tackling disease - with an energetic and lively stage presence.
On the surface then, their inexorable rise to prominence has been as smooth as a speed boat powering across calm waters. But every great success story usually leaves something in its wake. The tale of The Wiggles is no different.
The official history of the band appears as the stuff of dreams, a chance meeting and a routine assignment propelling the previously ordinary boys to a new life as top-selling, globetrotting artistes.
Anthony Field, Murray Cook and Greg Page, three of the group's founding members, met at Macquarie University in Sydney, where they were all studying to become preschool teachers. Thrown together by a classroom exercise that involved writing songs for young children, the trio quickly found they were doing something they loved and had a talent for.
Field would later approach Jeff Fatt to join him, Cook and Page in The Wiggles - the pair had once performed together in The Cockroaches, an Eighties Aussie rock band which enjoyed modest success - and the foursome subsequently wrote and recorded a series of songs that would form the basis of The Wiggles's first album. Released through an imprint of the Australian Broadcasting Company, that debut would achieve platinum sales and plant their first footsteps on the road to worldwide fame.
Success has not been without its challenges. Page left the group in 2006 for health reasons after being diagnosed with Orthostatic Intolerance, a condition he still suffers from, and which induces fainting fits and overwhelming periods of fatigue.
It was also revealed earlier this month in the Australian media that Page has more recently fallen on hard times, after a series of investments turned sour following the onset of the global financial crisis. He may yet be forced to sell his house and his large collection of Elvis Presley memorabilia (estimated to be the fourth largest in the world) to meet his financial obligations.
But the show, of course, must go on and Page was replaced without rancour in late 2006 by Sam Moran as the "yellow" Wiggle, and it is this revised line-up of "blue" Field, "purple" Fatt, "red" Cook and Moran who will take to the Flash Forum stage on May 13 and 14.
So far so not so bad. But what if an important page of that remarkable history had somehow been torn loose sometime in the last 20 years? And what if on that page lived an historical figure who might just be to The Wiggles what, say, the late Syd Barrett was to Pink Floyd?
Famously, Barrett was Pink Floyd's original creative force - writing both See Emily Play and Arnold Lane, two standouts in the group's remarkable back catalogue - before leaving the band in 1968 to pursue a solo career and later to live a largely reclusive life in Cambridge.
Such a man exists in the story of Australia's foremost children's entertainment act too. His name is Phillip Wilcher - a man occasionally referred to as the "fifth Wiggle". And yet Wilcher is not mentioned on the band's official website, which otherwise offers an extended history of the group's rise to fame.
According to his biography, Wilcher was asked by Field to help write and finance The Wiggles's first album in 1991, but would leave the group shortly after its release to pursue his dream of writing classical music. "I have never wanted to be anything else but a composer," he says on his website. His contribution to that debut recording has since been recognised by the Australian Record Industry Awards.
Few details now remain of Wilcher's brief time with the band: a couple of early 1990s video clips - which feature the band in polka dot shirts rather than their now-signature bright tops, big belts and dark trousers - are preserved for posterity on YouTube. Subsequently, even their debut album was later re-recorded by The Wiggles in the mid-1990s, removing all trace of their previous band-mate's involvement.
For his part Wilcher is almost as coy as the fab four about those days.
He rarely comments about this period in his life, preferring to let the music he writes now represent who he is. He also seems anxious not to be misrepresented in print. Indeed, when I contacted him last week to ask him about his experiences in The Wiggles I received a prompt and courteous reply which informed me that he was unwilling to comment.
That should have been the end of the matter - but it wasn't.
A few days later Wilcher got back in touch, saying he had reconsidered my original request. He was prepared to go on the record, but only on his terms. "I offer you the following," he wrote, "and ask that if you quote me, you quote me in full."
Here then is his unabridged statement: "I have never regretted for one moment having missed out on any fame or fortune that may have come my way had I stayed with The Wiggles. Success means different things to different people.
"I consider myself to be a highly successful composer and my creativity has sustained me well throughout my life. I am blessed. I am here to make music, not money. I am satisfied and more than content with my life. I always have been.
"However, in this their 20th anniversary year, I feel it would be fitting for Anthony Field to pay me a certain debt of gratitude [note to reader: the word "gratitude" was marked in bold in Wilcher's e-mail] I have long felt owed me by way of thanks if indeed what he and The Wiggles are effectively celebrating is the recording of the 1991 eponymous debut album. Without me, that album which afforded them a contract with the ABC to produce a further two CDs, would never have happened. I wish them well."
Exactly what that "debt of gratitude" is, remains unclear.
But what I wondered was the official line on the "fifth Wiggle". An inquiry to the band's publicity office in Baulkham Hills, Australia elicited this swift response from Kayley Harris, their publicist.
"Phillip performed on the original album recording with The Wiggles in 1991," Harris informs me. "Like all Wiggles albums, the album was produced by Anthony Field. This album was recorded at a demo studio and featured the cast before The Wiggles created their unique look (the red, blue, purple and yellow shirts).
"Phillip appeared on two film clips but left the group after only a couple of live performances. By the time The Wiggles filmed their first feature video, he had left. As the quality of the first album was more like a demo [than a finished studio album] and the group had changed their look, The Wiggles re-recorded their first album and video."
Harris signs off by telling me to "keep wiggling". I will, but I won't stop wondering either.
The Wiggles will perform at Flash Forum on Abu Dhabi's Yas Island on May 13 and May 14. Tickets are on sale now.