Again, ruminations in preparation for the Grateful Dead conference:
What does it mean to play on the edge? It seems that this expression (or figure) would indicate a state of playing where the mind is on the verge of losing touch with the fingers. Facing the potential loss of control, the mind either embraces the situation or becomes agitated. If the former, "playing on the edge" takes on the sense of a letting go. The "letting go" is experienced as ecstatic freedom, where new possibilities are allowed to occur.
But the figure of the "edge" is spatial. It is the border of something. Playing on the edge, as a spatial imagery, implies a willingness to go beyond the border or boundary. But the edge also cuts, it is the edge of a knife blade for example. The playing must cut an object. This cutting produces something new, an event.
Music's spacing is thus improvisation. Improvisation, in principle, must always already be ahead of itself, moving toward the unforeseen, to the "place" of edge. Improvisation places the player at the boundary of the edge, the jumping-off point to the pure possibility of the impossible. This is the paradox of improvisation: that its possibility relies on what is impossible, that is, the spacing of cutting that is non-contiguous with that which is cut. The border cannot be cut because as soon as it is, a new border appears.
We return to the idea of touching the border in improvisation at another time. Indeed, we must develop the thinking of the touch in music along the lines that Derrida has recently laid out in his book on Nancy.