Jazz played using musical modes rather than chord progressions.

In bebop as well as in hard bop, musicians used chords to provide the background for their solos. A song would start out with a theme, which would introduce the chords used for the solos. These chords would be repeated throughout the whole song, while the soloists would play their parts. By the 1950s, improvising over chords had become such a dominant part of jazz, that sidemen at recording dates were sometimes given nothing more than a list of chords to play from. Creating innovative solos became exceedingly difficult.

In the later 1950s, spurred by the experiments of composer and bandleader George Russell, musicians frustrated with ever repeated chords tried the modal approach. This meant that the bassist, for example, did not have to 'walk' from one important note of a chord to that of another - as long as he stayed in the scale being used and accentuated the right notes within the scale, he could go virtually everywhere. Similarly, the pianist would not have to play the same chords or variations of the chords, but could do anything as long as he stayed within the scale being used. The overall result was more freedom of expression.

In fact, the way that a soloist creates a solo changed dramatically with the advent of modal jazz. Previously, the goal of a soloist was to play a solo that fit into a set of chords. However, with modal jazz, a soloist must create a melody in one scale (typically), which could be potentially boring for the listener. Therefore, the goal of the musician was now to make the melody as interesting as possible. Modal jazz was, in essence, a return to melody.

One of the best selling jazz albums of all time in this modal framework is Miles Davis' Kind of Blue. Included on these sessions was tenor saxophonist John Coltrane who, throughout the 1960s, would explore the possibilities of modal improvisation more deeply than any other jazz artist.