Despite K-pop band BTS' record high sales of "Map of the Soul: 7," the relatively tepid performance of the album's title track, "ON," on the Billboard singles chart indicates that American radio airplay remains a formidable barrier for the septet.

This week, "ON," the lead single from the latest BTS album, slipped sharply to 68th on the Billboard Hot 100 singles chart dated March 14 after debuting at fourth on the weekly chart the previous week.

The No. 4 spot was the strongest showing BTS has achieved on the Hot 100 so far, but compared to the massive feat "7" achieved on the Billboard 200 albums chart, the latest Hot 100 chart results seemed somewhat out of tune.

In its first week, "7" scored sales of 422,000 equivalent album units in the United States, the biggest week for a group in four years and the highest for 2020, according to Billboard.

The album debuted atop the Billboard 200 albums chart last week before stepping down to third on the list this week, powered by solid physical album sales and online streaming.

The contrasting result on the Hot 100 by "ON," however, is largely attributable to the dearth of radio airplay for BTS music in the US, a major element in the compilation of the Hot 100 singles chart.

A recent article contributed to Billboard pointed to the formidable reluctance of American radio stations to air non-English songs.

"Radio stations have historically resisted playing non-English songs, and BTS has been no exception, despite the group's growing mainstream popularity," Tatiana Cirisanoa, a journalist, said in the article posted on March 3.

"There was little to no radio play to support the album's singles, and no merchandise bundling, meaning the album's sales were almost purely organic," the journalist said.

Another contributing article posted on the website of the Grammys earlier this month hinted that BTS' huge success in the US without the backup of radio airplay may indicate a major change in the musical landscape.

"It is further proof of a musical landscape that continues to shift toward streaming ... While radio certainly hasn't disappeared, BTS' journey to the top of the US charts is strong evidence that streaming has completely replaced radio in terms of breaking new artists into the mainstream," The Grammys' contributing writer Nate Hertweck said in the article. (Yonhap)