Sounds like a quintessential children’s lesson in “things that don’t go together,” since no one has better exemplified the country-as-adult-contemporary trend than the 39-year-old diva. But there aren’t any looming crossover hits on her ninth album, Timeless, where — startlingly — McBride expertly remakes 18 songs from the golden age of country without putting a Streisand-style spin on any of ’em, including truly old-timey oldies by Ernest Tubb and Hank Snow. “Even though I grew up singing this music, I’ve spent the last 14 years singing every other style but this music,” she acknowledges. “And this was so effortless, it felt like home. I realized that everything else I’ve done for the last 14 years has been like work.”

The oldest carbon date is 1952, for Hank Williams’ “You Win Again”; the most modern choice was Tammy Wynette’s 1976 “‘Til I Can Make It On My Own.” There was no cutoff date, originally: “We tried cutting a Reba song, because I grew up listening to her,” says McBride, “but it’s like we got to a certain era and it just felt like, nope, doesn’t fit.” A few cuts, like a mournful cover of Johnny Cash’s “I Still Miss Someone” with harmonizer Dolly Parton, were rearranged, but overall “I really wasn’t interested in doing updated versions of the songs or even making them my own. Which sounds bizarre. But ‘Rose Garden’ will always be a Lynn Anderson song. It’s never gonna be a Martina McBride song. Ever. And it was fun to borrow certain phrasing or intonations from the original artist, as a nod. You really can’t sing [Buck Owens’] ‘Love’s Gonna Live Here’ another way. Plus, it’s way more fun to sing like Buck than me.”

Speaking of “You Win Again,” McBride has picked up the best female vocalist of the year at the CMAs the last three years straight, and her last seven albums have all gone platinum (three triple-platinum), but all commercial bets are off. “I guess it’s surprising that I would do this at this time in my career,” she figures. “This is the kind of project I think people expect you to do later, after you’ve kind of had your regular career.” From Celine-style belting to thumping Ernest’s tub: That’s our kind of crossover.

addCredit(“Martina McBride: Andrew Eccles”)