The all-male a cappella group Home Free apparently never heard of the three-strikes rule.

The group tried out for each of the first three seasons of the NBC reality competition “The Sing-Off,” failing to make the cut each time.

Undaunted, the five-member group — this time with Tim Foust on bass and Austin Brown on lead vocals and a new focus on country music — auditioned once again.

With the fourth time proving the charm, Home Free not only got picked up for the show, but emerged the winner.

Besides the national exposure, Home Free received a recording contract with Columbia Records and $100,000 in cash.

“It’s been surreal ... the whole experience,” says tenor Rob Lundquist, who will make his Atlantic City debut with Home Free 9 p.m. Friday, March 7, at the Golden Nugget Atlantic City. “Going into ‘The Sing-Off,’ we were saying let’s not be the first ones to be kicked off. It turned out the way it did, and everything has been icing on the cake.

“All the groups were so talented — the first day coming in we were blown away by all the talent. None of us thought were going to win — we went in every day just thankful we were there, and having a good time with it, and not taking ourselves too seriously.”

The group is now in the midst of 32-city tour with fellow contestants VoicePlay and The Filharmonic. Home Free will be performing material from the show, including a joint medley of songs by fun, as well as tracks from its latest album, “Crazy Life” (Columbia).

The group’s sixth record features two numbers from “The Sing-Off” — its cover of the Johnny Cash classic “Ring of Fire,” and a medley of Hunter Hayes’ “ Everybody’s Got Somebody But Me,” “Wanted,” and “I Want Crazy — among other covers and original tunes.

“We have some stuff that’s super-country and stuff that leans more in the country-pop style, and we take some popular songs and make them sound country,” Lundquist says.

Home Free has undergone multiple personnel changes since forming in 2000 in Mankato, Minn. Brothers Adam and Chris Rupp have been the constant amid the changing players.

“The membership changes have been pretty crazy,” Lundquist says. “I’m there almost six years. At that point, it wasn’t even a full-time thing. We all had side jobs and would gig when we could.”

Once Foust and Brown came on-board a few years back, Home Free decided to pursue music full-time, and something clicked with the sound.

“We had always done country in our act before, but had never focused on it,” Lundquist says. “It just made sense. Tim is from Southeast Texas and Austin is from Georgi. They brought all the country flair, and we decided to go that route and it worked.”

Having finally coalesced as a group seemed to pay dividends when it came time to compete in the seven-episode competition, which took place over two weeks in December.

“I think we had a little bit of an advantage over some of the groups because we had been a touring group for so long and had sung with each other for so long,” Lundquist says.

Following the national TV exposure from “The Sing-Off,” the troupe doesn’t have to worry about getting a warm reaction from the audience.

“The crowds before didn’t know us — we would have to win them over, and usually we would by the end of the show,” Lundquist says. “Now we step on stage, and they all know us, and are hooting and hollering before we sing our first note.

“That’s been a huge change and a very welcome change. It’s been a blast. On the Sing-Off Tour right now every show is sold out or close to sold out. They’re just going nuts — it’s very surreal and crazy.”

Group found kinship with Jewel, Stockman

For Home Free’s Rob Lundquist, getting to interact with “The Sing-Off” competition’s celebrity judges, especially Shawn Stockman, below right, of Boyz II Men and singer-songwriter Jewel, below left, made their experience that much more meaningful.

“I grew up listening to Boyz II Men,” Lundquist says. “Getting to meet Shawn Stockman was just huge. In that first episode, when we were doing ‘Cruise,’ I made eye contact with Shawn. He was nodding his head and going, ‘Yeah.’ I was going, ‘Oh, my God, this is my life now, this is crazy.’ They were all super-nice and very approachable.”

Another highlight was getting to know the real Jewel while rehearsing and performing “Have Yourself a Merry Little Christmas” with her on the show.

“She’s just a riot, you can’t get a straight-up answer from her, she was always goofing around,” Lundquist says.

But the music industry veteran also offered a professional helping hand.

“She hit us up after the show, and said if we need any help with publishing or whatever ... it’s been amazing, it’s very cool,” Lundquist says.