RADWIMPS’ fifth album served as a fresh start for the quartet. For its previous releases, the Kanagawa band developed its reputation with Britpop-indebted rockers mixed with faster cuts inspired by nu-metal, complete with rapped passages. Its songs thrived on youthful energy, with vocalist and primary songwriter Yojiro Noda writing frantically to capture that vigor. But he changed it up for 2009’s Arutokoroni No Teiri, taking his time to lay out the details of the tracks while also pushing RADWIMPS to explore new sounds. Symbolically, the group ditched the naming convention it had used up to this point. Whereas every prior full-length release was just the band's name plus a number, here it made a clean break to announce the dawn of a more eclectic period. Arutokoroni No Teiri is full of firsts for the group. “Nazonazo” marks the debut of electronic elements—in this case, synthesizer melodies—into the band’s music. “Nanoka” dips into blues rhythms and eventually introduces a full-blown choir, foreshadowing the more dramatic sound the group would adopt when it entered the world of film soundtracks in the 2010s. “One Man Live” and “Magic Mirror” spotlight Noda’s higher vocal register. The group also spends a fair amount of time working in a slower, ballad-like style. That would become one of its strengths in the years ahead. On Arutokoroni No Teiri, RADWIMPS is using Noda’s newfound attention to detail to get the most emotional impact out of these tracks. “Tayuta” teases sonic catharsis, but the band always holds back to keep the tension present, which makes the moment when “Order Made” explodes all the more impactful. For an outfit once filling every second with guitar squall, RADWIMPS now plays with space on sparse numbers such as “Marchen and Greteru.” This is the moment RADWIMPS embraces the sound that would define it in the next decade.