"Only [harmony series no. 17]" arose, as part of the whole collection of harmony series pieces, as something of a special case. Each of the other pieces in the series tries to understand harmony as the sum of potential relationships between (human) performers. Consequently in these works, the actual harmonic relations are not prescribed, just the structure for these relationships. "Only" attempts to reframe this question in a different context. Here one is asked, under the aegis of a poem by Kenneth Rexroth, to listen to an environment for a long time, occasionally responding (by making a long tone). In performing the piece, I encounter the following questions: "What, in the sum of things occurring now, do I hear, and how do these things harmonize themselves? How can I express my relation to this harmony as a tone? What effect does this have on my continued listening? How will I spend my time? Do I experience the void or just imagine it?"