The sophomore album from Australia’s electro super-duo demonstrates that three years of touring, remixing, and DJing have provided the boys ample time to solidify their sound. On the “Girl and the Sea,” spacey, disco-influenced house pop matches with a perfect proportion of fuzzed-out synths and coolly aloof vocals. The occasional killer shark-attack dance beat still emerges (this year’s version of “Are You the One?” is “My People,” accompanied by its spectacularly disarming video), but Apocalypso largely plays to the band’s newly identified target audience, rewarding blissed-out club hoppers and festival junkies with a rich smattering of blompy house beats and throbbing acid lines.