Derya Yıldırım takes the stage at a packed house in Berlin’s Gretchen club one night in November 2019. “It feels like a home-crowd tonight,” she says before launching into her hit, Nem Kaldı (“A Song”) by Aşık Mahzuni Şerif, featuring frenetic saz cut through by wah-wah guitar arpeggios and Doors-like organ riffs. The music verges between joy and sadness, offers something close ...