The birth of music videos can probably be traced back to the early promotional clips that The Beatles filmed in the 60's. But videos really didn't take off until the mid-to-late 70's. That's why it's so funny to see Hall & Oates obviously making fun of the practice in the early 70's, and, with such a melancholy song! Also consider the fact that they would go on to become mainstays of MTV and every video show on every network in the 80's!
And check out Daryl Hall looking more like a member of Queen than what would become one of music's most iconic mainstream pop duos!