This tumblr is amazing (especially if you're a music student): http://musictheoryaugmented.tumblr.com/
Eighteenth-century audience: when a piece modulated to flat VI
Every time somebody calls an instrumental work a song
Adding a new line to the curriculum vitae
Just jamming to some Hildegard
Grading figured bass homework for a freshman class
I could keep going all day with this, but this will do for now. Even if you don't understand most of the jokes, the reaction gifs are a merit of its own to check out. (I mean, look at that cute bunny).