Progressive jazz (also known as modern jazz) is a type of music that formed from inclusion of elements from other musical genres. One such result was the creation of jazz fusion. It was primarily developed on the west coast of the United States in the late 40's and early 50's. Progressive jazz is typified by an experimental, non-melodic, and often free-flowing style of modern jazz, especially in the form of highly dissonant, rhythmically complex orchestral arrangements. Read more on Last.fm.