There’s something a little off-key in the male world of American country music, and dang if them good ol’ boys ain’t none too happy about it.

A duo of fresh-faced singers called Maddie and Tae have overtaken many of the industry’s biggest names – including Brad Paisley, Keith Urban and Tim McGraw – to reach the top of the Billboard Country Airplay chart.

The fact that two female teenage newcomers find themselves on top of the pile with their debut single is unusual enough, but what has really shaken up the establishment is that their hit, Girl in a Country Song, is a biting parody of the popular “bro-country” genre that glorifies machismo, partying and beer-swilling while women ride along silently in pickup trucks and look pretty in cut-off denim shorts and bikini tops.

“I got a name, and to you it ain’t ‘pretty little thing, honey or baby’,” the duo, both 19, sing in the steel-guitar-heavy track that laments the passing of an earlier era in country music in which they say women were treated with respect. “Now we’re lucky if we even get to climb up in your truck, keep my mouth shut and ride along down some old dirt road we don’t even wanna be on,” the song continues.

An accompanying video supports the song’s status as an anti-sexist “bro-country” backlash, reversing the familiar roles seen in the work of artists such as Jason Aldean and Luke Bryan, and presenting three men dressed in skimpy girls’ clothes and cowboy boots, washing pickup trucks and gesturing provocatively at the camera.

The reaction from some of the pioneers of bro-country appears to be less than complimentary. “The bros aren’t laughing,” said the Washington Post, noting a near-total absence of praise or congratulation for Maddie and Tae from established artists.

In a sulky interview in another newspaper, Brian Kelley of the duo Florida Georgia Line at first denied even knowing of the song, which was released in July and currently has more than 14 million views on YouTube.

Kelley, who co-wrote the hit Cruise, in which he fantasises about riding in his Chevy pickup with a girl from Georgia in a bikini top and “long, tanned legs”, then defiantly announced: “I don’t know one girl who doesn’t want to be a girl in a country song. That’s all I’m going to say to you.”

To some experts in country music, the Maddie and Tae song could be part of the beginning of the end for bro-country, described by Travis Stimeling, assistant professor of music history at West Virginia University’s School of Music, as “male artists in their late twenties, often with rugged good looks, singing about how great it is for some cute little thing to climb up in their pickup trucks and ride out into the country to drink”. He said the duo, Maddie Marlow of Texas and Taylor Dye of Oklahoma, who have been writing and performing together since they were 15, had found a clever way to deliver their message. “They’re offering a satirical commentary that’s more acceptable than a direct critique,” Stimeling said.

“Like others before them, such as Shania Twain and the Dixie Chicks, they use comedy, satire and parody as a way to criticise the dominant male establishment. It’s a pretty smart song in terms of lyric and interesting wordplay, and has that iconic bro-country sound, a slow tempo and bass-heavy beat reminiscent of Florida Georgia Line.”

Stimeling, however, jokingly takes exception to the girls singing about two legends of country music in the line: “Conway [Twitty] and George Strait never did it this way, back in the old days”.

“Conway Twitty did do it that way. Tight Fittin’ Jeans was one of the most overtly sexual songs in his entire repertoire, and George Strait certainly did his share of leering, just in a different way,” said Stimeling.

Others, such as Ron Pen, director of the John Jacob Niles Centre for American Music at the University of Kentucky, say the song has little to do with traditional country music and is basically pop. “You have these two cute 19-year-olds, singing about it and doing it. The song is part of a parodying response to bro-country and something that traditionalists don’t like very much; they see it as rock’n’roll rather than country.”

In interviews Maddie and Tae have said the idea for the song came to them as “a lightbulb moment” in Nashville as they talked about the current hits in the country charts.

“Oh my gosh, it would suck to be a girl in those songs,” Marlow said. “We love all the artists we’re poking fun at. We love modern-day country, but you never get to hear what the girl has to say. So we wanted to write a song from a different perspective to say, ‘Hey, boys, it’s hard being the girl in these songs’.”