Music for imaginary films that turn out to be real films

This morning I turned on my iPod and listened to what I thought was the KEXP Song of the Day. It sounded cinematic--like it could be film music, with bits of ambient audio and foley stitched together in a montage playing under the music. But then I realized I was listening only to the audio track of a video clip. "That's interesting" I thought--a new way to place music in a context of an action even without footage, or composing music with foreground and background elements, where the music supports a narrative (like lyrics).

Music for imaginary films is by no means a new idea, but the fact that I perceived it that way is somewhat of a revelation--for me anyway.

This is the video clip on Radiolab re: Words