The Dominant Ninth and Tonic Seventh in the Upper Tetrachord of the Major Key

Pieter van der Merwe, Derek B. Scott, and Norbert Linke have all written about the freedom with which nineteenth-century composers—especially those writing music for social dance and repertoires influenced by social dance—treated the upper tetrachord of the major key, an essential factor in the history of extended tertian chords and more generally in the history of still more complex harmonies. Examples total about 60; theirs and most of mine come from the 19th century waltz repertoire.