If LCD Soundsystem's third record will indeed be the band's last (as main man James Murphy has indicated), at least they're going out on top. Not since New Order's mid-'80s heyday has a band seamlessly fused dance music with rock music all the while reconciling an indie spirit with the mainstream. Though Murphy is reluctant to acknowledge his place in the mainstream ("You wanted a hit / But that's not what we do"), at 40 years old, surely he's self-aware enough to recognize the disingenuousness of those lyrics — "Drunk Girls," the first great punk song of 2010, is destined to be a summer smash. The other eight songs on the hour-long (yes, these songs average about eight minutes) This Is Happening are no less potent, especially the Bowie-esque "All I Want," the driving "You Wanted a Hit," and "I Can Change," in which Murphy gives his most tuneful vocal performance, singing "I can change / If it helps you fall in love." More obliqueness from Mr. Murphy? People usually don't change, especially at his age. So, is LCD Soundsystem's supposed swan song a put-on? A catchy, danceable exercise in archness? Maybe not, because Murphy sounds serious in the record's numerous references to going home — as though he's ready to put LCD Soundsystem to bed. If he is, at least he left us with the most successful formula yet for dance rock.