It was the video of Gangnam Style, and in particular Psy's signature horse-riding dance, that pushed him to global stardom last year after it was posted on YouTube and turned into a viral sensation.
A satire on the luxury lifestyle of Seoul's upscale Gangnam district, it has become the most-watched YouTube video of all time, registering more than 1.5 billion views since it debuted last July.
Reactions to the latest electro-dance song were mixed but the video - showing the quirky singer's signature self-mocking humour as well as the new hip-swivelling dance - left more fans impressed.
"The beat is quite catchy! I'm sitting here shaking my hips side to side even though i have no idea what he's saying," said one YouTube comment.
"Mark my words. This WILL be the second video to make it 1,000,000,000," said another commentator, while some others said "R.I.P, Harlem Shake," in reference to another viral hit that swept the world recently.
Gentleman contains more English lyrics than Gangnam Style in a
clear nod to the singer's new found global audience.