The Ancient Greek Heraclitus was the first Western philosopher to develop a cogent theory of the unity of opposites. In his theory, Heraclitus makes clear that it is possible to see opposites as both divided and connected:

“Collections: wholes and not wholes; brought together, pulled apart; sung in unison, sung in conflict; from all things one and from one all things (B10)

As the same thing in us are living and dead, waking and sleeping, young and old. For these things having changed around are those, and those in turn having changed around are these.(B88)”

In music, we are often confronted with large-scale works, such as sonatas or multi-movement suites, or indeed united works comprised of varied sections. These works will typically involve contrasts of tempo, mood and texture, and the task for the pianist is to bring out those contrasts in full while also holding together the unity of the work as a whole. In this respect, the unity of opposites is a useful philosophical tool for understanding how this may be achieved.

One aspect to this is the idea that both a given thing and its opposite are in fact two elements of the same unity. This is not unlike Jung’s concept of the shadow and the ego; the two are seen as negative versus positive, or unconscious versus conscious, but in fact both form an integral part of the whole person and must be reconciled in order to promote harmony. The movements of a sonata typically explore varied regions, but something that is at times hard to define ties them together and means that the experience of hearing them together is more than merely the sum of the constituent parts.

Schubert’s last piano sonata in B flat major (D.960) offers us two particular challenges that illuminate this. The first of these is in the overall structure of the work. There are four movements; the first two are predominantly moderate or slow in their pace and extended in their material, and the last two faster and shorter. In addition, the first two movements are emotionally intense and at times bleak, whereas the latter two are more positive, purposeful and resolute in mood, providing answers to the questions that had been asked earlier. The pianist must convince the listener not only that these movements belong together, but that they constitute a progression leading to a logical conclusion. This is most challenging in respect of the emotional continuity of the work, because if this is not maintained, it can easily leave the listener feeling that the second half of the sonata is inferior to the first, or that the drama has in fact concluded with the end of the second movement.

The second challenge is in the first movement exposition repeat, where Schubert introduces a transition passage containing intentionally disruptive and disturbing material that appears nowhere else in the movement. This is too much for some pianists, and they simply omit it. And yet disruption is already part of the work; we have barely proceeded past the first phrase, a calm chorale-like melody, when we are confronted by a menacing, uncomfortable trill in the bass. The same interval (the semitone) that describes the trill begins the transition passage. It is not only integral to the movement, but forms an essential part of the whole work.

How can we reconcile what is disparate? By perceiving each aspect as part of a unified whole into which opposites are deliberately introduced in order to expand the horizons of that entity. It is also possible to conceive the progress of a work in the sense of an enantiodromia as defined by Jung, in which when a thing is pushed to an extreme, it causes its unconscious opposite to emerge and eventually is overcome by that opposite. Jungian individuation holds that this process is one of integration and that from it is generated a whole that is complete. We might also recall the discourses of Osho, in which weighty spiritual matters were interspersed with politically incorrect jokes; this deliberate paradox was employed as a tool for transformation by reaching beyond the conscious mind.

The disparate elements in music do not all appear at the same time, but often in sequence, and yet they are all compresent in that they exist together concurrently. One element implies, perhaps causes, perhaps reflects another. And those elements interrelate; that is to say that they change and are changed by each other. Just as one cannot step into the same river twice, it is not possible to simply “repeat” a passage of music. The music on repetition is changed by its context even if it is ostensibly the same textually. An adept interpreter will make this contextual change explicit in performance, by reflecting the passage of the emotional journey in terms of dynamics, phrasing or other changes to the sound-world.

Another means of emphasising unity is to follow the practice of great pianists such as Grigory Sokolov and Radu Lupu of making minimal breaks between the sections or movements of a work. When this is done, it preserves the flow of the work through establishing a continuity of ideas. Sometimes this continuity also makes a harmonic point, as is the case in the transition between the second and third movements of Chopin’s third piano sonata (op. 58). It also forces the listener to pay attention to the transition; rather than the usual coughing and shuffling for a few seconds, they are compelled to concentrate and focus their attention in the same way as is the performer intent on conveying the overall structure and unifying features of the work.