BTS Fans Make 'Investigate Spotify' Twitter Trend, Claim 'Butter' Streams Not Being Counted On 5/25/21 at 11:51 AM EDT Fans of South Korean pop group BTS have rallied in criticism of the music streaming service Spotify amid claims the platform is filtering out how often they listen to the group's new single Butter. BTS is one of the most popular groups in the music genre known as K-pop, and the band's fanbase is large and extremely active on social media. On YouTube alone, the music video for "Butter" has garnered more than 200 million views despite being uploaded just a few days ago on May 21.