This is a significant achievement not only because it's the brand-new duo's very first single, but also because it's only the second radio single from a female artist or group to reach No. 1 this year on a country airplay chart (Mediabase or Billboard), following Miranda Lambert's "Automatic." (Carrie Underwood's "Something in the Water" and Lambert and Underwood's duet "Something Bad" topped Billboard's Hot Country Songs chart, but that chart takes more than radio airplay into consideration.)

And if you look at the Billboard Country Airplay chart alone, "Girl in a Country Song" is the first song to reach No. 1 since Underwood did so back in October of 2012 with "Blown Away." Yes, based on that chart it's been two long years since a female artist reached the top.

By comparison, in 1995 five female artists reached the top of the Billboard country singles chart. The following year was even better: Of the 28 singles topping the that chart, 12 were from women.