The album title cuts to the chase. Like all good DJs, Mark Ronson is first and foremost a collector, the kind of guy with untold 45s lining his loft. In his production work for Lily Allen and Amy Winehouse, he proved to be one of music’s wonkiest wonks, bringing encyclopedic pop knowledge to geeked-out party music. Some other things that Ronson collects: vintage keyboards and cool friends. His third album is full of chiming synths and guests that run from Simon Le Bon to Ghostface to the London Gay Men’s Choir. The single “Bang Bang Bang” pairs Q-Tip and the New York duo MDNR in a buoyant electro trifle; “Glass Mountain Trust” finds D’Angelo doing his best Prince impression. It could be a messy grab bag, but Record Collection hangs together as an album. Ronson is the rare DJ-producer who is as fluent with melodies as he is with beats. (Check the fiendishly catchy “Lose It [In the End],” sung by Ronson himself.) He doesn’t just love old music, he understands it: In songs like the stormy “Somebody to Love Me,” he does for 1980s synth pop what he did for 1960s girl-group soul on Winehouse’s Back to Black, pushing past kitsch revivalism to evoke a timelessly moody romanticism. He’s a connoisseur with a heart.