One of my favorite artists, Prefuse 73, is one of the many acts playing Wicker Park Fest. At the risk of sounding pretentious, his (mostly) instrumental, (kind of) ambient pieces are urban pastorals--warmer than DJ Shadow's Endtroducing..., less frenetic than J Dilla's Donuts, more inviting than Boards of Canada. If Millennium Park sounded like something, it would sound like Prefuse 73. I can't vouch for him as a live act, but I'd highly recommend most of his recordings, which you can sample at his Web site. If anyone from eighth blackbird is reading this: collaboration.
Speaking of eighth blackbird, they're hiring, or at least they were, but you never know.