Hips swinging, South Korean rapper Psy launched the dance and video of his new song “Gentleman” at a packed Seoul concert on Saturday, with nearly 160,000 tuned in online to see if he could carry off a repeat of his megahit “Gangnam Style”. The video for “Gangnam Style” is the most watched ever on YouTube with more than 1.5 billion hits, and its horse-riding dance has been imitated by thousands around the world, from Eton schoolboys, to UN Secretary-General Ban Ki-moon
