Morgan Wallen and Chris Stapleton are in rare company. The pair — who trade vocals on a new song called "Only Thing That's Gone" — are two of three country singers since 2015 to dominate Billboard's all-genre album chart in back-to-back weeks.

Dangerous: The Double Album is the No. 1 album on the Billboard 200 for a second straight week on the strength of record-breaking streaming numbers. During its debut week, the album earned 265,000 album-equivalent units, of which 74,000 were pure album sales. During week two, those numbers dropped to 159K equivalent albums with 22K in pure sales. That it's a double album with 30 songs gives him an advantage, but Dangerous more than doubles the week's No. 2 Billboard 200 album, by Pop Smoke. Luke Combs' What You See Is What You Get is the No. 2 country album.

That's a lot of numbers. What's significant is how long it's been since a country artist went back-to-back on top of the Billboard 200. Stapleton's Traveller did it last after he performed "Tennessee Whiskey" at the 2015 CMA Awards. The last album to top the chart during its first two weeks was Luke Bryan's Kill the Lights, in Aug. 2015 (per Billboard). In some ways the achievements are comparable, but in other ways, they are not.

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Traveller totaled over 177,000 equivalent albums after the televised performance, but 153,000 were full album sales (per Red Light Management). The next week it was No. 1 with 124K equivalent albums and 97K in pure sales.

Bryan's Kill the Lights topped 300,000 in pure sales and equivalent albums its first week atop the charts, numbers that were sliced by two-thirds for week two. Comparing sales and chart data across different eras or even different decades is a fraught task because listening habits are so different. The only rule of thumb that is timeless is that more is always better.

Historic sales/streaming numbers don't always speak to big things to come for an artist and his or her album. Stapleton's album (released in May 2015) was a footnote for six months before he performed on television with Justin Timberlake. Overnight he sold out his tour and assured himself a very comfortable lifestyle. In the next year, he'd win CMA, ACM and Grammy Awards.

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Kill the Lights was not a critically hailed album, thus aside from a few nominations for a Karen Fairchild collaboration, it was largely ignored as a project come awards season. Dangerous: The Double Album is not eligible for either the 2021 Grammy Awards in March or 2021 ACM Awards in April, meaning fans will need to wait until November to find out how it's viewed in the minds of the industry.

The answer to this question will also speak to if the industry views streaming data as a reliable metric in measuring overall value and "heat."

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