There are at least two projects called Illinois:
These are photos from concerts where Illinois played, so they may be of other bands that played the concert as well.
Lollapalooza 2007 Aug 3 - 5, 2007 Chicago, Illinois, United States Uploaded by Josh5180
Lollapalooza 2007 Aug 3 - 5, 2007 Chicago, Illinois, United States Uploaded by Kumo
Silverchair
The Polyphonic Spree