There are at least two artists with this name:
1. A popular American rock band
2. A psytrance artist
(If you are scrobbling tracks here from Chicago - Music From The Miramax Motion Picture, please fix your tags.)
1. Chicago is an American rock band formed in 1967 in Chicago, Illinois. The self-described "rock and roll band with horns" began as a politically charged, sometimes experimental, rock band and later moved to a predominantly softer sound, generating several hit ballads.