Sweden is loaded with rock bands trying to resuscitate the psychedelic sounds of the late ’60s. So maybe it’s unsurprising that the most internationally acclaimed such outfit would switch gears. On Dungen’s fifth studio set, mastermind Gustav Ejstes downplays chaotic crunch for mellower, piano-led jams verging on jazz fusion. When the guitars do freak out (say, in “Samtidigt 1”), it’s a jolt, and the proggish prancing often catches a warm groove — “Fredag” has R&B in its rumble. But much of 4 feels like beautifully baroque soundtrack music desperately seeking a movie about a rainy afternoon.