Bill Callahan has always been one of rock’s greatest mysteries. Not because he refuses to talk about his songwriting process (“There isn’t one, I just get out of bed”) or his personal life (he married Hanly Banks, a filmmaker who in 2012 came to make the documentary Apocalypse: A Bill Callahan Tour Film). Growing up, his parents worked as language analysts for the National Security Agency, and he was forbidden to tell his friends what they did for a living, so you can say he came by his inscrutability naturally.

One of the finest songwriters of his generation, in 1989 he began releasing lo-fi music cassettes under the obfuscating sobriquet of Smog, a name as metaphoric as it is evocative of the dark, melancholy world that he visits in his songs. He followed the cassettes with 11 strange, fraught albums, all with a strong sense of isolation and space—dark and melancholy ruminations that made you question everything about yourself, and about him. But good luck ever getting the musician to elaborate.