The chart was established in 2010—it was one of 21 genre-specific song charts launched by Billboard that year—with the issue dated January 23,[1] and ranks the 25 best-selling digital singles in the world music genre.[2] The recording of "Somewhere Over the Rainbow" by Hawaiian singer-songwriter and musician Israel Kamakawiwoʻole has dominated the ranking for most of its existence, with a total of 345 weeks at the top spot, appearing on all 590 weekly issues of the chart as of the issue dated May 1, 2021,[3] including a 116-week stretch at number one from the chart's inception until April 2012.[4] Another notable chart-topper is Psy's "Gangnam Style", which stands in second place for most weeks at number one with a total of 50 weeks between 2012 and 2014, and third overall for total weeks on the chart with 362.[5] Over the years, many other K-pop artists appeared on the chart, with some reaching the top position, most notably BTS, who achieved a record 27 number-one singles,[6][7] followed by girl group Blackpink, with seven number-one singles on the chart.[8][9]