"Songs in the Key of Z" is a delightful compilation of outsider music

Songs in the Key of Z  is the title of a book and two compilation albums created by Irwin Chusid in 2000. You can listen to Songs in the Key of Z, Vol. 1 and Songs in the Key of Z, Vol. 2 here. The albums contain a fine selection of songs by "outsider musicians." Similar to "outsider art," Chusid defines "outsider music" as "crackpot and visionary music, where all trails lead essentially one place: over the edge." There's some pretty out-there stuff on these albums, and I can't get enough of it. Songs in the Key of Z has popularized a handful of obscure musicians to a wider audience, such as Daniel Johnston, Joe Meek, Jandek and Wesley Willis.