Isabella Gomez Sarmiento Fans in Seoul waiting for the comeback concert by BTS watch a drone light show. The biggest band in K-pop before it went on hiatus in 2022 so its members could perform mandatory military service in South Korea, BTS released its sixth album, Arirang, on March 20. Jung Yeon-je/Getty Images hide caption On Friday, K-pop's biggest group, BTS, released its highly anticipated new album, Arirang. It's the first project featuring all seven members of the boy band in nearly four years, following a hiatus for mandatory military service in South Korea. Individual members — particularly Jimin and Jung Kook — have achieved significant solo success since then, but the return of BTS in full force signals a massive moment for the genre the group helped turn into a global powerhouse. In 2018, BTS' album Love Yourself: Tear became the first K-pop album to ever top the Billboard 200 chart. The band would go on to reach that milestone five more times in four years.…