There was a ripple of activity at the entrance of Mandarin Oriental’s 23rd-floor Mandarin Bar late Saturday night. The hubbub was caused by “American Idol” Season 8 contestant Scott MacIntyre, recognizable for his sagebrush-ian mound of curly hair and also for the cane he uses to navigate his path.

Across the bar, leaning slightly over a synthesizer, Frankie Moreno halted and said, “Whoa! We’ve got a celebrity in the audience!”

MacIntyre, who is sight-impaired, and his wife of three weeks, Christina, took a seat just feet from where Moreno and his six-piece band had set up. Smiles stretched across the musician’s faces, as none of the performers expected MacIntyre to show up at this unscheduled gig.

“If you want to come up and do something, just give us a thumb’s up, and we’ll do it,” Moreno said, alerting his band on the fly that there would likely be an unannounced guest star joining the fray shortly. Minutes later, Christina led her husband to the band, where he took Moreno’s spot and belted out “How Sweet It Is (To Be Loved By You)” and “Mandolin Rain.” The usually muted and mellow lounge, typically home to jazz performances, was slammed by then, the audience roaring over MacIntyre’s unexpected drop-in.

It seemed so random, but it wasn’t. This sort of thing has been happening pretty frequently in Las Vegas lately.

The way MacIntyre shows up to a Frankie Moreno show at Mandarin Oriental is no fluke: He was the featured performer earlier in the evening at the Blind Center of Nevada gala at World Market Center. At the risk of just throwing my own evening headlong into this tale, this is where my “Kats With the Dish” radio co-host Tricia McCrone, KLAS Channel 8 anchor Paula Francis and I were emceeing an event where 470 guests filled the 16th-floor banquet hall.

It was a wildly entertaining event, at least for us, and (inside joke alert), if you have not yet eaten your sorbet, please do so now.

During the program, Moreno sent text messages saying he was performing an off-the-radar show at Mandarin Oriental and to come on down after the Blind Center event. This information wound around our table to Blind Center officials who told MacIntyre that if he wanted to find a cool hang in Vegas on a Saturday night, to join this merry troupe.

Now would be a good time to mention that MacIntyre, who lives in Scottsdale, had never been to Las Vegas before Saturday.

“This is incredible,” he said after performing with Moreno and posing for photos. “Is it like this every weekend?”

“It can be,” I said.

You can’t script this stuff, and the vibe so difficult to attain is happening organically. The city’s reputation as The Entertainment Capital of the World was forged in such moments, which you cannot manufacture. Swagger is an elusive quality, and Las Vegas has it, still.

– by John Katsilometes