Olof Dreijer has made some of the best music of the 21st century, but there’s a good chance even many of his fans don’t know him by name. This is mostly his decision. He first appeared 26 years ago with his sibling Karin as the Knife . When Karin carried on that group’s theatrics and iconoclastic spirit into their solo work as Fever Ray , Olof slipped out of the spotlight. He did a few techno 12"s in the early 2010s—all of them good, one of them (“ OAR003 B ”) a classic—under the name Oni Ayhun. After the Knife’s final album, Shaking the Habitual , he withdrew from music almost completely. As a white man from Europe for whom feminism, anti-racism, and international solidarity were more important than a career in music, Dreijer figured he was best placed supporting artists less privileged than him—running a music school for refugees in Berlin, for instance, or remixing artists like Emanuel Jar, a Sudanese musician, activist, and former child soldier.…