Joni Mitchell

By irreducibly complex I mean a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.

Neil Young does throw in a major seven chord here and there, so if you're a new guitar player learning Neil Young songs, you'll learn some seven chords, and some different positions. Nothing too complicated, just enough to kind of open up your knowledge a little bit.