In the Shacklewell Arms in east London, the usual crowd of hipsters and indie music fans had been replaced by a throng dressed in leopard print, double denim and cowboy hats to pay tribute to the night’s headliner: Shania Twain.

“We thought we might have been scammed when we saw the ticket announcement,” said Jack, 28, who came with his sister Amy. “Why would she do a pub this small?”

There was a collective sense of disbelief among the lucky 200 ticketholders that they were about to see the bestselling female country artist singing in a dingy back room. Best friends Emma, 26, and Ava, 28, thought it was “so rogue” to see Twain in a pub that used to be their local.

The Shacklewell Arms was turned into an old-school saloon for the night to honour Twain, complete with a wall of complimentary cowboy hats and bandanas. Fans travelled from across the UK for the once-in-a-lifetime gig. Nathan, 35, from Scotland, covered in old merch, was here to see her for the eighth time. “Why is she doing this? I don’t care. I only usually get to see her in large concerts. So it’s special to see her up close and personal.”

Just minutes later, Twain bounded on stage and announced: “Shacklewell Arms! Here we go. Are you ready?” Then she launched into her new single, Dirty Rosie.

Once the song was finished, Twain, dressed in a black skin-tight bodysuit with matching boots, welcomed the audience “to [her] very first time in a small bar since [she] was a child”. “When I was a kid, I started on stages just like this,” said Twain. “They would say, ‘Ladies and gentlemen, welcome to the stage Little Miss Twain.’ And I would get up there and sing my country songs.”

For one hour, Twain was back to being a bar singer in a sweaty, cramped room. Every song was punctuated by a quick anecdote. No One Needs to Know was written in the room at a golf resort where she worked. Come On Over was a “very weak album title”, but it represented the “inclusive, welcoming” feel she wanted. Pat Benatar’s Hit Me With Your Best Shot influenced Twain to write That Don’t Impress Me Much.

The cosy atmosphere led Twain to ask about UK fan favourite songs. The crowd unanimously responded with When, a top 20 hit from Come On Over. So Twain dutifully treated the fans to a snippet of the chorus, followed by You Win My Love, Don’t Be Stupid, and From This Moment On.

Twain’s intimate pub performance is part of the rollout for her seventh studio album, Little Miss Twain, which comes out on 24 July. As Twain told the small crowd: “This album is all about the phases of my life before I got my recording contract. I was playing in bars from the age of eight years old until I was in my late 20s. Little Miss Twain was just trying to become a recording artist.”

The show also served as a warm-up for Twain as she prepares to play Wembley Stadium for the first time in her career, supporting Harry Styles’s 12-night mini-residency.

Three decades into her recording career, Twain’s star shows no signs of waning. Her enduring status as a cultural icon is partly down to her savvy musical efforts to always broaden her fanbase.

“She is the consummate crossover act,” said Elamin Abdelmahmoud, a Canadian culture writer and host of Commotion. “It takes a certain kind of brain to say: ‘Country music is fundamentally who I am, but that does not mean I have to sacrifice the ambition of pop.’ At one point, she was picking up the entire genre and carrying it on her back.” Not to mention, for many “millennial babies” such as Nathan, Twain was both the soundtrack of his childhood while also “bringing out new music for me to enjoy as an adult”.

In the Shacklewell Arms, Twain felt “complete” that she had made it back to the bar stage after 52 years. Though the same could not be said for some of the fans who expected Man! I Feel Like A Woman! to be the show’s closing song and instead got a cover of Cotton Eye Joe. Twain certainly would have heard the chants of “one more song” as she exited the pub.