Another artist that straddles the line between music and poetry is Wilco's Jeff Tweedy. He is probably the most important American songwriter of the last decade or so, because along with his brilliant band, he has explored the boundaries of both words and music in terms of creating imagery, telling stories, putting arguments forward, exploring emotion, etc. - in other words, all the things that are accomplished by poetry of the highest level. Here is an excerpt from "One Wing", from their most recent recording, Wilco (2009):

We may as well be made of stone
We can't be flown
One wing will never fly
Neither yours nor mine
I fear we can only wave goodbye

See what I mean? If you're interested in Wilco, and I think you should be, I would recommend the DVD concert documentary, Wilco Live: Ashes of American Flags (2009) where Tweedy discusses his impressionistic songwriting. I would also suggest listening to all of their albums in order from first to last to hear their astonishing growth (and some of the greatest rock music of this generation).