The story of how the word may have migrated from California to Illinois is complicated, and will be covered in a future post.
By 1915, jazz was being applied to a new kind of music in Chicago. The story of how the word may have migrated from California to Illinois is complicated, and will be covered in a future post. For now, suffice it to say that the Chicago papers were definitely referring to a music called "jazz" by mid-1915.