That melding is achieved most efficiently by means of an apparently natural, human gesture. Performers strive to create a shaping and shading of each phrase that is more than the sum of the motivic and harmonic units of which they are composed. The energy and flexibility which we acknowledge as artistic is also necessary to counteract the dull regularities of the frame. There are thirteen degrees of freedom in the movement of the arm alone, and to date no machine or neural net can accomplish the sophisticated coordination of that many possibilities, whereas trained pianists exhibit such refined motion without a second thought. Thus, it would be counterproductive to try to describe and hence define gestures exhaustively with respect to some precise recipe combining their musical components or their muscular embodiments.
Different combinations can achieve similar effects.
One might question whether these warpings capture the holistic character of gesture, but there may be a real contribution to one strand of the twisted cable, to use an earlier analogy. But we may compensate for the missing information we would wish to have found in historical sources by looking more closely at clues to be found in the preserved notations of scores. But just as typically, one reaches into the music's physical manifestation by the heuristic of simply sitting down and playing the piece - feeling what the hands must do to cover the notes at the right times, engaging in the plasticity or flexibility that leaps or passage work or sudden shifts demand of the body, and then inspecting one's bodily engagement for clues as to expressive correlates. I say ironically, since one would expect that music of one's own age would come with a gestural realization transparently encoded in the style as in the culture. The problem of fragmentation in culture and musical style almost makes historical reconstruction of a gestural language for, e.g., Beethoven, easier than for the interpretation of a work written yesterday.