On Tuesday South Korean K-Pop boy band BTS made their London stage debut to a packed O2 arena. THis comes as K-pop fever is sweeping the British capital ahead of the hugely successful group?s sold-out concerts. Reuters reports that BTS have gained a worldwide following, winning over fans across continents and helping popularize a music genre further. BTS became the first K-pop performers to have a no.1 album on the Billboard 200.