American Stories , his third album, is a gorgeous-sounding, meditative addition to his influential catalog Since co-founding Vampire Weekend 20 years ago and producing the band’s first three albums, Rostam Batmanglij has enjoyed a unique profile as a pop songwriter and studio wizard, especially for a guy whose sound never really left his old band’s highbrow sensibilities behind. When pop and R&B starting getting artier in the 2010s, and indie music began moving closer to pop, he helped to shape that transition with his contributions to innovative modern classics like Frank Ocean ’s Blonde , Solange ’s A Seat at the Table , and Haim ’s Women in Music Pt. III , as well as work for other top stars . A Rostam track might remind you of contemporary hip-hop just as easily as it might evoke chamber music, or incorporate musical elements that reflect his Iranian heritage while seeming wholly in step with whatever was happening next at the forefront of American music.…