Robert Christgau has been writing about music at the Village Voice for over 30 years now. His body of criticism is an inspiration to anyone who's serious about discussing popular art in a serious, grand way. As an added bonus, he's hysterical.
You can start anywhere on his exhaustive website to get fresh insights into artists he loves (Randy Newman, Steely Dan) and even the ones he hates (Radiohead). Here's a piece I've been enjoying lately, a glowing appreciation of Stevie Wonder's Songs in the Key of Life. Written in 1976, but it feels like it was published yesterday.