The act - Brothers Andrew and Mike Tierney and high-school chums Toby Allen and Phil Burton - formed in 1989 under the name the 4 Trax. By the mid-'90s, they had achieved a good deal of success - as Human Nature - Down Under performing original material as well as covers. But things went to a much higher level once it was suggested to the members that they familiarize themselves with the Motown repertoire.
"We had some mentors who told us we have something special, but if we want to learn about the great groups, we should start listening to Motown - the Four Tops, the Temptations, the Miracles, the Jackson 5," recalled Andrew Tierney during a recent phone chat. "So, that's how we got introduced to Motown.
"We are fans of all the different groups. But for us, Motown just really struck a chord. When we went out on tour, we wanted it to be like an old Motown revue. So, we put the suits on and we really channeled Motown, and it was fun to do.
"Finally Smokey Robinson heard about us doing the Motown songs as well, and everything fell into place for us to develop this particular part of our career."
"This particular part" of their career included a winter 2009 residency at Tropicana casino in Atlantic City, where they made their U.S. debut. Today, they are in the midst of a two-year run (which began in January 2013) at Las Vegas' luxe Venetian casino-hotel.
The group's original idea was to ask Robinson to join it on a song in the studio. But when the five vocalists met in a Los Angeles studio, Robinson insisted that his involvement extend beyond a solitary track. The pop immortal is quoted on HumanNatureLive.com as describing the troupe as "extraordinary vocalists who truly know how to entertain, and I knew that they would be hugely successful."
Borgata, 1 Borgata Way, Atlantic City, 9 p.m. today, tomorrow, Aug. 15 and 16, $39, 866-900-4849, theborgata.com.
On Twitter: @chuckdarrow