How important is music in anime?

[http://farm3.static.flickr.com/2277/2078044048_e546ec9e14_m.jpg|240x180px|Christmas #5 by Kevin Dooley on Flickr]

I've been thinking lately about music in anime.

Music's a complicated subject because it's so emotional, and because anime music exists independently from the show it's used in. Voice acting is integral to a show; fans rarely re-listen to lone audio clips of voice acting ("Kyon-kun, denwa" notwithstanding). But we'll listen to theme songs and background music in the car.

That's the rub. Music that works well on its own doesn't necessarily work well paired to an anime series. I'm reminded of a statement made by Shinichiro Watanabe (director of Cowboy Bebop and Samurai Champloo), in which he said that the danger of using Yoko Kanno (Escaflowne, Cowboy Bebop, Ghost in the Shell: Stand Alone Complex, Wolf's Rain, Macross Plus and Macross Frontier) as a composer is that her music is often so powerful that it overwhelms the scene. The visuals have to stand up to her music, as they do in the "Rain" sequence in the "Ballad of Fallen Angels" episode of Cowboy Bebop.

Great music attempts to tell its own story. It will have emotional highs and lows and subtlety. As such, great music is often bad to pair with animation, as the two conflict with each other, each trying to tell their own story. "Flight of the Bumblebee"'s specific emotional tone and progression won't match up with every happy or energetic sequence in an anime series.

And yet, there are plenty of beautiful, touching, emotional soundtracks in the world. How do they work? Were they paired with anime of similar visual power? What's the secret?

The secret lies with story. Great background music won't tell a story with the clarity and drive of a stand-alone piece by Tchaikovsky or Vivaldi. Background music is all about mood. Yoko Kanno's music evokes mood as reliably and powerfully as Ray Bradbury's prose.