Much has changed in the intervening decade and a half. Pop stars aren’t as grand scaled; country music now takes as givens many of the risks Ms. Twain innovated; and Ms. Twain divorced Mr. Lange following an outlandish tabloid scandal.

And yet Ms. Twain is not apprehensive about her return, 15 years later, with her fifth album, “Now,” on Sept. 29. “I really feel like I’m coming back into worlds that I already know,” the singer, 52, said one afternoon early last month in a room at the London West Hollywood hotel here. “Now” is, like most of her albums, not quite country music, though she has swapped the excess of her last albums for something smaller and warmer. It has little to do with country music’s traditional center, but to be fair, much of modern country music has little to do with what is thought of as country music’s traditional center.

By standing apart, Ms. Twain may well fit in, though the path hasn’t been clear thus far. The new album’s first single, “Life’s About to Get Good,” fizzled on the chart. But radio might not be Ms. Twain’s path, said Cindy Mabe, the president of Universal Music Group Nashville. “It’s the magnifier,” she said, “but frankly, does she need it? No. She’s a global icon.” She pointed out the breadth of Ms. Twain’s release plan — award shows in France and Germany, a concert in London’s Hyde Park, TV in this country and Canada, and much more — as proof that “no one has the reach that Shania does.”

As Ms. Twain spoke, she was preparing for this global rollout, surrounded by racks of clothes to wear for photo shoots and television appearances, and musing on another way the culture has changed during her break from promoting albums.

“It is way more acceptable to be different, to be a more normal shape,” she said, discussing how at her pop peak, she wore custom-made clothes when runway styles didn’t fit properly. “It’s actually fashionable to have a bigger butt now. I remember feeling, like, ‘I cannot get my butt into these pants!’”