The Chicago blues is a form of blues music that developed in Chicago, Illinois, by taking the basic acoustic guitar and harmonica-based Delta blues, making the harmonica louder with a microphone and an instrument amplifier, and adding electrically amplified guitar, amplified bass guitar, drums, piano and sometimes saxophone and trumpet. The music developed in the first half of the twentieth century due to the Great Migration (African American) when Black workers moved from the South into the industrial cities of the North such as Chicago. Originally, the Chicago Blues was street-corner based music. But after the music quickly gained popularity, it became a giant commercial enterprise. Soon the new style of music reached out and touched Europe, which led to many famous English rock n' roll bands to get their inspiration from the Chicago Blues.

At first, the Blues clubs in Chicago were filled with black performers, and the music itself was aimed for black audiences. Most of the Blues clubs were on the far south side of Chicago, so white people did not visit them. Later, however, more and more white audiences visited the clubs and listened to the music. This caused clubs to open up on the north side. In addition, more white men started playing the Blues after it became popular.

Chicago Blues has a more extended palette of notes than the standard six-note blues scale; often, notes from the major scale and dominant 9th chords are added, which gives the music a more of a "jazz feel" while remaining in the confines of the blues genre. Chicago blues is also known for its heavy rolling bass. Like Delta Blues, Chicago Blues often uses a harmonica and occasionally saxophones.