Improvisation is the instant creation of a new composition.
Earliest Jazz improvised by embellishing the melody. A 3-note chords stacked in intervals of a 3rd. A major triad chord is formed by the 1st, 3rd and 5th note of a major scale. A minor triad combines a minor 3rd and a perfect 5th. Six - Em, D, G, A, B, C. 2.