SEKAI NO OWARI scored its biggest hit to date with its third studio album, Tree. The band’s previous full-lengths set the template for its proven formula of rock, EDM and lyrical optimism, but with its 2015 release, the group committed to expanding its vision, introducing an even wider array of styles to its palette. Marching bands, choirs and accordions play prominent roles, as does the embrace of big-tent EDM. Tree explores sounds far removed from the traditional J-pop repertoire of piano ballads and midtempo rock strolls—and features some of the group’s most vulnerable lyrics. The foundational roots of the quartet’s sound—guitar, piano and Auto-Tune—remain, but SEKAI NO OWARI became even more eclectic on Tree. “Snow Magic Fantasy '' approaches chamber pop. The circus-themed “Pierrot”, with its accordion-guided melody, incorporates samples of animals and crowds cheering over electronic beats. The group is in a particularly experimental mode across Tree and isn’t afraid to go out on a limb. The LP’s huge commercial hit, “RPG”, is a song built on a marching beat, elements of polka, big choirs and Auto-Tuned singing. It’s an unusual melange of ideas, leading to a cathartic hook that makes everything click into place.