Know much about Steve Reich? How relevant is the music of Iceland to the music of today? To what degree of influence did the Pixies have on Indie Rock? Want to stay hip to what your students may be listening to?
If you're a general music teacher, more appropriately at the high school level, you should definitely check out Pitchfork TV. You'll find here an assortment of music related streaming videos. Of most interest to the music educator is the One Week Only section of the site where full length featured music documentaries are posted each week.
I'm certain there are ways for you to incorporate whatever it is you experience from this site to the classroom. While some of the videos may be deemed "inappropriate," it's up to you to decide how you'll utilize this resource.
BTW, Pitchfork TV comes to you by way of Pitchfork Media, a Chicago-based online music magazine I visit frequently to read up on music news and reviews of albums and performances.
The reviews published on Pitchfork Media are great examples of top notch music journalism. I have used a handful of them in my own class to help students better approach their own writing.
Check out a prior post of mine on the importance of Writing and Speaking Musically.