This year’s holiday season is particularly significant for Human Nature. The Venetian’s resident headliners celebrated three decades together last month as they made preparations for their annual series of Christmas shows, Human Nature Sings Christmas, Motown and More, which they performed in their native Australia for the first time. The week before they returned home, the vocal quartet released retrospective album Still Telling Everybody—30 Years of Hits in Australia, and upon arrival in Sydney received a special honor in recognition of their career achievements.

“We’re being inducted into the Aria Hall of Fame, which is like the Australian music industry’s Grammy Awards,” said Andrew Tierney, a founding fourth of the vocal quartet, on the eve of their transpacific travel plans. “It’s an unbelievable honor, so yeah, it’s very exciting. Nothing we ever expected. It kind of took us by surprise when we found out. We’re going to be performing at the awards night as well, so it’s going to be fantastic.”

Tierney, his brother Mike, Phil Burton and Toby Allen, who had been Down Under in May to receive the Medal of the Order of Australia, performed five Christmas shows for the fans who made them famous at Melbourne entertainment venue the Palms at Crown before heading back to Las Vegas to make merry inside The Venetian’s Sands Theater.

Last month also marked the sixth anniversary of Human Nature’s The Christmas Album, which forms the basis of the seasonal set list and was rereleased as a deluxe version in 2015. “Let It Snow,” “White Christmas,” “O Holy Night” and “Rudolph The Red-Nosed Reindeer” have historically been singalong staples of Human Nature Sings Christmas, with the album itself making numerous returns to the Australian Top 10.

This year might be different, as Still Telling Everybody debuted at No. 10 upon its release and is currently outperforming The Christmas Album. Both releases include “Please Come Home for Christmas,” which features Human Nature’s mentor Smokey Robinson sharing lead vocals with Burton. Robinson may not be able to work Las Vegas into his schedule this December, but he was onstage at the Sands Showroom in September to offer his congratulations on the occasion of Human Nature’s 2,000th headlining performance at The Venetian.

“We didn’t plan it that way,” says Tierney. “He was doing shows in town on Friday and Saturday, and he reached out on Tuesday.” Robinson was unaware he’d be in town to mark a career milestone for his protégés, but that’s just one of the miracles that occurred during the course of the relationship between the Motown legend and Human Nature. “The legacy and the impact he’s had on people’s lives, not only musically but culturally … he’s just such a treasure for this country and the world,” said Tierney. “Anytime he walks into the room, it’s a good time.”

The Venetian, 7 p.m. Tues.-Sat. (dark through Dec. 16), additional 2 p.m. show Dec. 22-23, starting at $55.51 plus tax and fee. 702.414.9000