In her essay, "Uses of the Erotic: The Erotic as Power," Audre Lorde makes a case for the erotic as a "source of… information" that is fundamentally nonrational in nature, reclaiming it from the domain of shallow sensation to which it is often relegated. In opposition to rational systems of thought (exemplified in Descartes' cogito ergo sum), the erotic provides an opportunity for a foundation of self cast in the often uncomprehended depth of our innermost feeling. Lorde writes:
... the considered phrase, "It feels right to me," acknowledges the strength of the erotic into a true knowledge… and understanding is a hand-maiden which can only wait upon, or clarify, that knowledge, deeply born." 
With erotic knowledge, feeling precedes understanding. Piano playing, too, offers knowledge sought in the darkness of unrecognition. Touching a key is always as much sensing as sensual. With other instruments, the physical sensation of plucking a string; the felt vibrations of a mallet; the way that breath transforms the human body into a powerful resonator: all of these interactions suggest a definition of music-making as a deeply embodied act. Even when touch is mediated by reed, bow, or mallet, this mediator becomes a sort of talisman that connects the instrument back to the body. One vibrates through a reed. One feels the flexion of the mallet or bow returning feedback to the hand.
With piano, the touch is always more ambiguous, and it is this combination of sensation with imagination that renders piano playing ultimately more erotic than athletic. Each manipulation of a key is a question that echoes Lorde, asking, "does that feel right to me?"
What creates this space for ambiguity is the piano's mechanism, which is neither fully tangible nor fully abstract. On the harpsichord or clavichord, tangible instruments, one can literally feel the "pluck" of quill or the strike of metal against string. On the organ, more abstract, each key is simply a switch that allows the already present, mechanized breath of the bellows to pass freely through a pipe. The piano lies somewhere in between, while possessing qualities of its own.
Crucial to the sensation of piano playing is its lack of weight transference. Pianists use their weight to balance the hand, control articulation, and achieve finer control of keyspeed, yet the key itself transfers no weight to the hammer. The hammer, for its part, starts out resting against the key, but at a certain point is released, flying freely toward the string. Its acceleration, and by extension its force, is determined only by the key's acceleration at the point of release. Mass is fixed. It would seem, then, that piano sound would be a single variable calculus.
Yet there are other variables. Key depression influences damper height, and damper height (how high the muting dampers are held above the string) influences the rate of decay or blossoming of a note's sound. The pedal adds a third dimension, multiplying the blossoming or decay effect of a single damper by allowing other strings to sympathetically resonate. By varying the relative activation of key and pedal (how deeply each is depressed), pianists can influence not only the shape of a note, but also its overtonal composition.
When a high school teacher of mine first directed my ear to these subtleties of piano sound, he confessed that he had always imagined such factors to act primarily as a musical guide for the pianist. Effects such as "blooming" a note's resonance with the pedal to achieve a kind of crescendo are more helpful to the pianist in feeling exactly what the dynamic of that next note should be than they are to an audience listening for the expressive shape of a line. The audience, for its part, will intuit the expressive shape of a line in retrospect -- they will sense that there has been a crescendo -- if the pianist is able to manipulate the dynamic of connected notes well.
But, by this logic, if listeners are able to pick up on such subtleties as an implied crescendo, shouldn't we be encouraged to put every effort into rendering audible those gradations of sound and pedaling (yes, even pedal crescendi) that can actually be heard? For, surely if listeners are already filling in gaps with their imagination, then, assuming that they can hear even a fraction of what the pianist hears up close, surely their imaginations will also amplify these barely perceived subtleties?
For these reasons, we can see that two fundamental aspects of piano playing are already imaginative at their core: (1) basic instrumental mechanics (being able to imagine the specific weight and interaction of hammer against string, amplified by pedal, always on a unique instrument in a unique hall) and (2) expressive playing (manipulating sound to communicate expressively to an audience through illusion or, better yet, suggestion).
Yet we can go one step further: into the very philosophy of playing. Glenn Gould used to say that it only took an hour to learn everything one needed to know in order to teach oneself the piano, but that teaching oneself the instrument could take a lifetime. The duality of this lifelong struggle is perhaps no better expressed than through the musicianship and temperament of Glenn Gould himself, whose creativity was only matched by his meticulousness. Gould's urge to mastery stemmed from this deceptive fact that the piano is a machine with finite noise-making parts that should theoretically be comprehensible and controllable, given enough time.
I used to interpret this formulation of piano playing as a challenge — the idea that one could somehow adjust and compensate for the deficiencies of any given instrument, let alone one’s own physical limitations from day to day, assuming the right preparation and through sheer force of will. Each performance becomes a kind of heroic struggle. These days, I prefer to think of each performance as an act of searching imagination, depending less on our ability to navigate this piece of clunky machinery than our ability to utterly transcend the circumstances, given the right frame of mind. In doing so, we arrive at a performance that we had perhaps not originally expected to deliver, but that is paradoxically more representative of “us” than if we had attempted to contort ourselves to produce an exact, desired effect.
In other words, we can do our best to understand the array of variables that go into performing a given piece on a given piano, assuming some blank canvas idea of what a piano should be, but pianos are such wildly temperamental creatures that we would do well to cultivate, equally, a sense of the sheer scope of how such variables might fluctuate on a given day. Such an understanding, in a rational sense, is aspirational at best. Theoretically, Glenn Gould is right. We can comprehend each of the variables with full lucidity if we isolate each and practice creatively. But in the moment of performance at an unfamiliar instrument, as we begin to take in each of those variables fluctuating in different ways all at once, the attempt to control our playing becomes a futile, self-defeating effort. We must fall back on a trust in ourselves, on a trust in the unique, embodied knowledge of being a pianist that, paradoxically, does allow for the creation of a physical connection to the instrument, even as the physicality continues to be largely imagined.
Just as Audre Lorde's definition of erotic knowledge depends on the construction, "it feels right to me," so must piano playing become a searching within oneself, of attuning one's body to a both a purposeful flow and a spontaneous, inspired choreography. By this definition, piano playing at its very best is an act of becoming, an act of imagination that rises to the circumstances and transforms not only the audience, but also the performer in its navigation of these myriad interactions (pianist to audience, instrument to audience, pianist to instrument).
: Lorde, Audre. "Uses of the Erotic: The Erotic as Power" Sister: Outsider, Random House, 1984, p. 43.
: Lorde, Audre. "Uses of the Erotic: The Erotic as Power" Sister: Outsider, Random House, 1984, p. 46.