Reversal and Notation

In chapter 4 I discussed a general definition of symmetry, a definition that binds together two distinct types of musical phenomena: “proportional symmetry” and “mirror symmetry.” By “proportional symmetry” I referred to the “harmony of parts with each other and the whole,” and I surveyed the various manifestations of that symmetry in Purcell's music: in the lengths of sections and phrases, in the gradual change of phrase lengths, and in the way in which sequences of sections of different lengths and from different movements are symmetrical with one another because of an equivalent tonal structure they outline. By the term “mirror symmetry” I referred to instances where there is “exact correspondence in size and position of opposite parts” and “equable distribution of parts about a dividing line or centre.” Mirror symmetry will be the focus of the following chapters, in which I will show various ways in which reversal plays a part in Purcell's fugal writing. While perception of proportional symmetry on a small scale (from the ticking of a clock to the equallength phrases of a simple minuet) is possible for listeners with even modest experience, mirror symmetries are often missed—their identification requires aural skills that, in many cases, are not only beyond those of most listeners but also beyond those of most professional musicians. In the next chapters I will present evidence of Purcell's intense engagement with mirror symmetry in his compositional process, and argue that mirror symmetry, and reversal in general, plays a lead role among those indiscernible levels of order with which his scores are overflowing.

Before technology gave musicians the ability to reverse sound itself (the sound envelope: attack, sustain, and decay), reversal was limited to the reversal of notated elements. Let us take the first three chords from the Minuet from the Suite Z. 660 (example 5.1), with which I already demonstrated basic proportional symmetry in the previous chapter. These three chords (I–V6–I) form a strict palindrome (example 5.1a), and for any analytical purpose the addition of articulation marks should not essentially change that palindrome (example 5.1b), especially if the articulation marks correspond to the order of the chords and therefore even enhance that palindrome.