I don't usually post stuff like this, if only because Youtube videos tend to be ephemeral, while blog posts get archived. But I figured this was all kinds of awesome, so. All credit for finding it goes to Sorrow-kun's Twitter.
In case the video gets taken down and future generations want to know what it was, it's a Vocaloid video by one "Cocoacigarette-P", who arranged various themes from Clannad (among others in other videos, but Clannad's the one linked here), and then drew the comics that accompanied the videos himself.
I've mentioned before that I'm not a huge fan of Clannad (I don't dislike it as such; it's just too depressing), but I am a fan of… I want to say "jazz", but I readily admit that I don't have the musical background to truly grok jazz. I just like the technical proficiency displayed, and how it all blends together perfectly.
And I love how Kaito (the guy on the drums) brings the comedy.