For fans acquainted with Múm’s earlier works, Sing Along to Songs You Don’t Know might seem an anomaly—the album’s opening tracks ditch the Icelandic band’s previous glitch-and-lullabye IDM for plain, old-fashioned indie pop. With shades of St. Vincent on “Sing Along” and “Prophecies and Reversed Memories,” the slow-motion soundtracks of Finally We Are No One and Yesterday Was Dramatic, Today Was OK seem far removed from the Múm on this record. It’s not that Sing Along to Songs You Don’t Know is a bad record, but Múm’s latest LP runs by a well-worn playbook, one that costs them their previously unique sound.