The 6/9 chord is a pentad with a major triad extended by a sixth and ninth above the root, but no seventh, thus: C6/9 is C,E,G,A,D. It is not a tense chord requiring resolution, and is considered a substitute for the tonic in jazz. The minor 6/9 chord is a minor triad with an added 6th of the Dorian mode and an added 9th, and is also suitable as a minor tonic in jazz.