The Hu, a Mongolian rock band that blends heavy metal and traditional Mongolian throat singing, has reached No. 1 on Billboard’s Hard Rock Digital Song Sales Chart.

The Mongolian rock band is the first act, since American heavy metal group Bad Wolves in February 2018, to top the Hard Rock Digital Song Sales with its first charting song.

Founded in 2016, The Hu combines heavy metal with traditional Mongolian instrumentation like the bowed stringed instrument, “morin khuur,” which translates as horsehead fiddle.

The band also incorporates the Mongolian guitar, “tovshuur,” a jaw harp called a “tumur khuur,” along with guttural throating and bombastic bass and drums.

When the band released its first two videos, “Yuve Yuve Yu” and “Wolf Totem,” in September last year, it immediately went viral with now respectively 16 and 10 million views on YouTube.

And now, after some initial buzz and media coverage in January, “Wolf Totem” bows at No. 1 on Billboard’s Hard Rock Digital Song Sales chart, according to Nielsen Music. Also, “Yuve Yuve Yu,” debuts at No. 7 on the same chart.

The band’s name, The Hu, is the Mongolian word for human being. The band members call their style “Hunnu Rock” inspired by the Hunnu, an ancient Mongolian empire, known as the Huns in western culture. Some of the band’s lyrics include old Mongolian war cries and poetry.

The Hu is at the moment preparing for a Europe tour in June and a brief U.S. tour in October, to perform its nine-song debut album, “The Gereg,” a term that was used to describe a diplomatic passport from the time of Chinggis Khaan.