References to the "song" in "The Idea of Order at Key West" function as an extended metaphor for art itself: the actual product of the artist and the inspiration. While the "song" represents just about any creative product, it's no accident that the term "song" is probably most logically associated with a poem. Stevens wanted this connection to be clear.
The song is also set in juxtaposition to another recurring image (stay tuned for a detailed discussion): the sea/water, which represents, among other things, inspiration or the muse. When you're reading (and rereading) "The Idea of Order…" try substituting poem or painting for song. Of course, it seems a little strange when you read that she sang her painting, but you'll get the idea that Stevens is on about art in general here, not just poetry.
- Line 9: A work of art and its inspiration are separate things. Once the piece of art has been created, it operates (it sounds) independently of its inspiration.
- Line 15: The inspiration, the muse, does not make the art, the artist does.
- Lines 38-40: The sea became the sea she created with her art. The artist here has made something new, a new reality to be responded to, reacted to, inspired by. It becomes a new muse. It is this inspiration, that colors the speaker's perception of the sea and the lights after the singing stops.