Last month, I revealed how the major tritone progression is the only progression that permits stepwise-equivalent voice leading between root-doubled complete triads. If more than four voices are involved, it is common (all other things being equal) in voicing major triads to weight the root the most, the fifth the next most, and the third the least. The second movement of Dvořák's Symphony No. 9 features three tritone progressions in measures 1, 22, and 120. The second instance is higher than the other two, and involves exclusively woodwinds -- six woodwind players, to be exact. Dvořák assigns two players each to the half-step lines (Ab-G-Ab and Db-D-Db), and one player each to the whole-step lines (Db-B-Db and F-G-F). This results in a doubling of both major triads such that there are three roots, two fifths, and one third -- exactly the distribution among the first six partials of the natural overtone series.
Next month, I will explore what it takes for a chord to voice lead smoothly to its tritone partner.
