This train of thought has been in my head for some time and I'm curious to see what other people think about it. I need to use a few examples to make my point.
If you listen to Fiona Apple's first two albums, she has a very particular sound - the arrangements that go with each song have certain characteristics that are immediately identifiable if you were to hear a song by her you'd never heard before. You could say "that's Fiona Apple!" If you watch the movie "I Heart Huckabees," almost immediately upon hearing the soundtrack, you'd say "that's Fiona Apple," except that it isn't - the composer was her producer, Jon Brion.
In 2003, she recorded her third album, "Extraordinary Machine." The album was shelved by Sony because they felt that there were no tracks that would make a good single. Personally, I think the 2003 recording is amazing - when you listen to it, it sounds like Fiona Apple. However, it's apparent that a lot of her sound - which comes from those arrangements - is really Jon Brion's sound. Sony had the album re-recorded and produced by Mike Elizondo, Eminem's usual producer, and when you hear the 2005 re-release, it doesn't sound like Fiona Apple. The arrangements make SUCH a difference.
Rilo Kiley is another example. Their fourth album, "Under The Blacklight," was also produced by Elizondo (it was the first time he produced an album for them). The album has a much "poppier" sound to it, much like the re-release of "Extraordinary Machine." Again, it's the influence of Elizondo's arrangements stepping to the forefront.
For Antony and the Johnsons "Swanlights," Nico Muhly created arrangements for two songs, "Ghost" and "Salt Silver Oxygen." I sent the songs to a friend thinking he'd enjoy them, and being a Muhly fanatic, he immediately asked if Muhly was involved in some way - at that point, I didn't know he had been.
So now we bring things around to Joanna: how much of what we love about Ys and HOOM is really the sound/influence of her producers/arrangers? Obviously she had to approve of the arrangements, but the construction of these arrangements is the creation of another person. I've never listened to much Van Dyke Parks or anything Ryan Francesconi has done aside from "Eleven Continents," but how much does Ys or HOOM sound like music created by Parks and Francesconi? People often gush about Ys's arrangements, which are unquestionably beautiful, but is that really Joanna? A lot of the arrangements on HOOM are fantastic as well, but how much of it is really Joanna? I remember the first time I heard "Colleen" and I felt that it was SUCH a diversion from her earlier work that I couldn't like it right away - that is the result of Francesconi's influence.
It's an interesting thing to think about!