Tag endings are somewhat related to turnarounds in their basic harmonic structure, butplay different roles in tunes and complete performances. A tag ending occurs at the veryend of a tune, repeats a chord sequence (which in the course of subsequent repetitionsbecomes harmonically transformed), and has an indeterminate duration. Only the finalrepetition of the tag ending progression is harmonically closed with a clear confirmationof the tonic. Its basic role in the performance is to provide a satisfactory, coda-like endingwith a final improvisational flair. As Miles Davis demonstrated on his many recordings,tag endings may take on a life of their own—especially with Herbie Hancock, Ron Carter,and Tony Williams in the rhythm section—and frequently exceeded the length of his solos.2Tag endings and turnarounds often share similar chord progressions: the only differencebetween the Imaj7–vi7–ii7–V7 and the iii7–vi7–ii7–V7 is that the former begins on the tonicand the latter on the mediant chord. These two chords, Imaj7 and iii7, are said to befunctionally equivalent and are frequently used to substitute for one another. Figure 13.6illustrates a iii7–vi7–ii7–V7 tag ending progression realized with Model II of keyboardplaying. Each measure displaces the Charleston rhythm by a half beat.Each of these chords can be further substituted by a secondary dominant 7th and,subsequently, by a TR/X7. Since a tag ending progression is usually four bars long, wecan demonstrate the use of two harmonic techniques that will double the rate of harmonicrhythm in each measure. The technique of dominant saturation combines two dominant7th chords, diatonic or chromatic and its TR/X 7 (or vice versa) next to each other. Theuse of ii7–V7 diminution technique expands any dominant 7th chord into a local ii 7–V7