It's been over 40 years now since Donny Osmond made his Las Vegas debut. Back in February of 1972, the Osmond Brothers appeared on a double bill with Petula Clark in the Circus Maximus Room at Caesar's Palace. So how has Sin City changed over the past four decades? From where Donny is sitting these days, Vegas hasn't really changed all that much.

"I've worked probably every hotel imaginable here in town, hotels that don't even exist anymore. But I'm still working for Caesar's, the Flamingo part of Caesars (Group). So I guess that nothing has changed in 40 years," Osmond laughed.

Donny was in a somewhat nostalgic mode when he and I spoke on the phone recently. As he and his sister were getting ready for yet another series of performances of "Donny and Marie Live," that 90 minute-long show which has been wowing crowds in Las Vegas since September of 2008, which is when this brother & sister team first began headlining at the Flamingo Hotel & Casino.

"I've been in this business a long time, Jim. I've seen 'em come and go. That's why (my sister and I are) pretty grateful for this stint in Vegas. Especially starting in '08, just before the crash of '08 and beginning on '09, we've been able to sustain it. So we're pretty grateful," Osmond stated.

Mind you, the audiences who come to Las Vegas just to see this legendary brother & sister act performing live on stage together are pretty grateful as well. They're thrilled to find themselves with tickets to the show that's repeatedly been voted "The Best of Las Vegas." Not to mention seeing the singing sibling who were voted “Best Performers of Las Vegas” back in 2012.

"To be able to have a hit show in this town is a pretty nice accolade," Osmond admitted. "But we leave it all onstage, Jim. We try and give (our audience) as much a show as possible. I think that's probably one of the reasons why (Marie and I have) sustained (here in Las Vegas). This is the work ethic that I learned clear back on 'The Andy Williams Show.' "

Speaking of Andy Williams, Donny recently folded a tribute to that late crooner into "Donny and Marie Live." Where Osmond sits on a stool in a spotlight and -- while clips of he & his brothers' many appearances on the old Andy Williams variety show play on video screens in the background -- Donny sings Andy's biggest hit, "Moon River."

"I learned a lot from (Andy Williams). I used to stand in the wings as a little 7 year-old kid. (My brothers and I) were his opening act. And we would do our numbers and open the show. But then I would stand in the wings and watch (Andy work)," Osmond continued. “He had this demeanor onstage. When (Andy) said something onstage, it was like E.F. Hutton. Everybody would listen. Not only to hear him sing but to tell little stories, to tell quips between songs."

And Williams not only showed Osmond how to hold an audience in his hand, he also taught him one of the real keys to becoming a professional singer, which is learning how to breathe properly while you're performing onstage.

"I remember one time when (Andy) pulled me aside and said 'Donny, I like the way you sing. But I need to show you how to breathe.' He said 'If you know how to breath properly, you're going to sing properly.' Now that's a broad stroke statement. But without that proper diaphragmatic breathing, you can't sing properly," Donny explained. "I always appreciated that (Mr. Williams) took the time to show this little kid -- I was probably 10 at the time -- the proper way to breathe in order to sing properly."

Of course, being able to properly use your instrument is a key skill for a singer. But when you work in Sin City, as Donny and Marie have for nearly 5 years now, there are other issues that performers constantly have to worry about, including the dreaded Vegas Throat. Which is what caused Osmond to bow out of nearly two weeks of  shows in the Flamingo Showroom, leaving Marie to perform solo while he then went on vocal rest.

"If people complain about it, I say get over it because we're in the desert. You're gonna get Vegas Throat sooner or later. And I've been working this town since I was 7," Donny stated. "What's been interesting is that you can kind of get acclimated to a certain extent. But (Vegas Throat) will catch up to you eventually. (Which is why) you're constantly drinking water, especially what with the energy that (Marie & I) put out onstage."

And speaking of energy, Osmond remembers getting a little guff from the folks at the Flamingo when he first discussed the tech side of "Donny and Marie Live."

"At the Flamingo, they (initially) thought that I was crazy with the amount of lights that I demanded that we bring in. Everyone was telling me 'Donny, you're over-doing it. You're over-doing it.' But over time, I'm vindicated because they say the production of this show is amazing," Donny enthused.

But what keep people coming back to see "Donny and Marie Live" isn’t just this show's terrific production values. But -- rather -- the legendary brother & sister team that just simply refuses to let their show grow stale, which is why they're constantly folding in new songs or bits of business.

"Marie and I constantly change (this) show. It's not the same as when we opened up," Donny admitted.

Which is something that the folks at Caesars Entertainment clearly seem to appreciate, Donny & Marie make a concerted effort to give this show's return customers something new to see. Which is why they've signed Donny & Marie to appear in the Flamingo Showroom through the end of 2013 and discussions are already underway to get this these two to extend their Vegas engagement through 2014 and beyond.

Which might be enough for some performers, but we are talking about Donny Osmond. He's already looking beyond the lights & the glitz of Las Vegas to find other fields to conquer.

"I'm gonna let you in on something. I'm producing a television property that I've developed over the last three or four years. It's probably going to be launching over in England," Donny stated. "And I've talked to -- I can't disclose which network yet -- but I've talked with one of the big networks about this concept. And they are extremely excited about (this project). And it has to deal with variety television."

So are we talking about a return of the sort of old TV variety show that Donny and his sister used to appear in? Sadly, no. Osmond seems to think -- given the way people's viewing habits have changed over the past quarter century -- an old-style television variety show just wouldn't work with today's audiences.

"I don't think that we can bring it back exactly the way that The Carol Burnett Show, The Donny & Marie show, The Cher Show (were). You can't bring back exactly that format. But what I've developed here that the network really, really loved is a way to bring (the variety show) back to a certain extent and still maintain that social media aspect that we have all become familiar with "Idol," "Voice" and "X Factor," those types of shows," Donny explained. "So (this new project is) an amalgamation of those types of things but with a lot of heart & soul. Hopefully, you'll hear (more) about it in the next few months."

But in the meantime, there's this month's worth of performances of "Donny and Marie Live" to get through. And after a few weeks away, Osmond was clearly chomping at the bit to get back up onstage and start entertaining those folks who are visiting Las Vegas.

"My wife and I had this conversation last night. She said ' When are you going to act your age?' And I said 'Well, I am. In my mind, I'm still 20,' " Donny said. " I mean, there are times when you just don't want to go onstage, whether you're sick or tired or whatever. But you leave it backstage when the curtain goes up and you give 'em a show."

"Those people (out) in the audience, they might not all be fans. But you really try and make 'em fans (before) they walk out," Osmond concluded. "Make sure that they walk out with a piece of your personality."

Which is perhaps "Donny and Marie Live" has turned into such a long-running success for the Flamingo Showroom. Because this brother - sister act is savvy enough to mix their old school show business skills with some of the best production values found along the Strip today. The results are a 90 minute-long show loaded with great stories, singing & dancing that you won't soon forget.

By Jim Hill/Special for

Las Vegas, NV – 05/08/13