Music by artists such as Taylor Swift and Lady Gaga could disappear from the video app TikTok from Thursday. The world’s largest music company Universal Music announced on Tuesday that it had been unable to agree on an extension to the licence agreement, which expires on January 31. In an open letter, Universal Music argued that TikTok was “trying to build a music-based business, without paying fair value for the music” and accused TikTok of “bullying” them into taking a deal “far less than fair market value and not reflective of their exponential growth.” TikTok also allows music created with…