Of all the many peculiarities surrounding Coldplay’s upcoming Mylo Xyloto — a concept album, oversize teardrops, xylophone toes — none was quite so unexpected as the promised Rihanna–Chris Martin duet, “Princess in China.” Rihanna, on a Coldplay rock opera, as the lady love interest in a vaguely futuristic foreign land? Huh. The result, which debuted last night on Dutch radio, is disappointingly thin on plot points, but “Princess in China” is perhaps not as crazy an undertaking as we’d originally thought it to be. Which is to say: It has synthy pows and a sweet Rihanna vocal, but it’s still a Coldplay song. Rihanna adapts well to the sweeping hook and the copious “ooohing”; she sounds natural, if slightly less sassy than usual. And Chris Martin has apparently constructed a world in which he gets to turn down Rihanna’s romantic overtures — certainly a ballsy move on his part. That brings us to one more important note: Vulture was totally wrong about the content of “Princess in China.” Who knew that Mylo would be the one doing the dumping? Our bad.