There is a Zen riddle that replies to its own question. ‘Does a dog have the Buddha nature?’ the riddle asks. ‘Answer either way and you lose your own Buddha nature.’ Faced with a mystery about divinity, according to the riddle, we must always hover, uncertain, between the two possible answers. Never, on pain of losing our own divinity, are we allowed to decide.
(Morton Feldman) 
That quote, from New York School composer Morton Feldman, places us in an awkward position, which is certainly the intent of the original Zen riddle, Joshu’s MU, often assigned to new monks as their first inquiry. The riddle, or koan, tells us Joshu’s answer to the question, “Does a dog have the Buddha nature?” Joshu says, “NO”. Anyone studying this koan knows, as the monks in the original story would have, that “all sentient beings have Buddha Nature”, so what’s with this “NO”? Joshu’s “NO” is a method—it vibrates in the student’s mind until it breaks open in a moment of intuitive recognition of the Emptiness of the duality of having and not-having. Understanding is not caused by the koan, but is not independent of it. Conditionality in Buddhist metaphysics is layered and discontinuous: “The effect follows upon the cause, but it is not produced by it. It springs up, so to speak, out of nothing.”  This springing up “out of nothing” is at the heart of music improvisation, and is central to both artistic and mystical practice. In this talk, I’ll explore some parallels between the disciplines of improvisation and meditation, revealing some of the mysteries in both making—and listening—to music.
A few terms, at their most abstract: “music” is a temporal art. It appears in time, and we recognize it by assembling a sequence of sensations, called “sounds”, in linear order, assisted by memory and expectation. In other words, sounds are happening all the time, we separate some from ambient noise—by recognizing them as something we’ve heard before—and subconsciously stringing them together like we do with spoken language.
To plan a sequence of sounds is called “composition”, which happens before re-producing the sounds for an audience, which is then called “performance”—from the Old French parfournir, “to bring to completion”. To produce sounds for an audience without a previous plan is called “improvisation”, from provisus—to have prepared. To improvise is—literally—to do something without having prepared. Another word for improvisation is extempore—outside of time. To act extemporaneously—“on the spur of the moment”—is to hover outside of time, because preparation creates time. When I plan this presentation for, say, a week from Friday, the concept “a week from Friday” appears in my mind. Is it too much to say that that day, twelve days from now, does not exist until I make the plan? Until I conceive of it, give birth to it, in what space does it exist? And if I die before next Monday it dissolves from even that abstraction, never—in my consciousness—to occur. This understanding—that “time” is only an idea—is a classic Buddhist insight. So, if composition defies death—as all planning does, imagining and relying on the predictability of a future—then improvisation defeats death. Improvised actions, created in “real time”, do not rely on the prayer “may I live longer” for their realization, their becoming real. Improvisation destroys time.
Improvisation can appear at any point in the creative process: in the act of composition, in both composition and performance, and in performance only. In each case, the skill required is presence, or acting based on perception and experience “in the moment”. T.S. Eliot says it like this:
For most of us, there is only the unattended
Moment, the moment in and out of time,
The distraction fit, lost in a shaft of sunlight,
The wild thyme unseen, or the winter lightning
Or the waterfall, or music heard so deeply
That it is not heard at all, but you are the music
While the music lasts.
These are only hints and guesses,
Hints followed by guesses; and the rest
Is prayer, observance, discipline, thought and action.
T.S. Eliot 
Eliot, in harmony with Buddhist understanding, tells us we’re mostly distracted, lost, with so much left unseen. Discipline is required to become found. Every meditative tradition trains us to focus attention in the present, away from thoughts of past and future (which is what most of our distractions consist of). This is why “planning defies death”. Thinking of the future is always a fantasy—who knows what will really happen, even a moment from now? And death is both the greatest unknown and our certain future.
We may think of time as linear—imagining a long horizontal line bisected by one point, called “now”. To sense that point is impossible, because there’s delay in the circuits of perception, but to attend to currently available perceptual information, which would thus be the immediate past, is called “being present”. This is a metaphoric way of talking about whether our attention is focused on what’s happening in the immediate sensory field or on the content of thoughts, which could be about situations that are distant from the immediate field. Locality in one symbolic point becomes a metaphor for “presence” in space as well. “Be here now.” Again, the conception is of an infinite expanse surrounding a single point, called “here”. In space, perception of distance implies horizon, which becomes the goal, the site of the Other, and the possibility of movement—all of which are necessary conditions, along with not seeing the Other as human, or self, of conquest. Empire arises from desire. Where desire is unformed, the future cannot solidify, remaining the softest of thoughts: “What will happen?” And presence undercuts desire, which without the dream of attainment melts into its innocent sister: appreciation. In music, appreciation in its most “present” sense listens “vertically”, to sounds as they happen, rather than through desire’s “horizontal” listening of thesis, development and return, the mileposts of the heroic narrative. And so unlike composition’s emphasis on linear form and development, improvisation plays the sounds “as they happen”, attentive to what happens next, but never knowing what will.
This image of improvisation as “future-free” immediacy is great, but may give the wrong impression. Improvisation is in fact often misunderstood, largely through the projection that the music is unprepared, as the word implies. Similarly misunderstood is a Zen practice called shikan taza, which means “just sitting” (rather than concentrating on a meditation object, for instance), and which seems to imply that practice and practitioner need no skills or necessary preparation. But both improvisation and Zen are undertaken—performed—in a context of significant training and conditioning. The relationship between what is learned and practiced, and what emerges extempore is causal, but like the koan, not linear. Just as the jazz musician practices scales and stylistic patterns but will never perform those patterns exactly, the Zen student sweeps floors, chants scriptures, and chops vegetables, not because those particular activities are the locus of realization—and not because any activity can be a locus of realization—but as a training in steadiness, precision, perseverance, and surrender, the necessary skills for (just) sitting.
An apocryphal story about Thelonious Monk says that he never “practiced”, but that he sat and improvised freely, all morning, every day. It is apocryphal not necessarily for being untrue, but because it misrepresents the research process. A 1957 recording of Monk at home reveals him methodically preparing a version of a standard, I’m Getting Sentimental over You.  He seems to use improvisation to find the characteristic sound he wants, then solidifies it, note for note, into a version he’ll remember, repeating, refining, correcting, and, yes, composing, until the details of the song are set. Then in performance, of course, it opens wide, becoming the template for a new free-ranging improvisation. In Monk’s practice, as this story imagines it, immediacy is the necessary foundation for both research (composition) and the eventual performance. Here you might listen to a bit of Monk playing “I’m Getting Sentimental Over You” in 1960.
Morton Feldman also used improvisation as a compositional method, but in a different way. He said this about his process:
As a rule I write in ink. It sharpens one’s concentration. Erasure gives you the illusion you’re going to a more meaningful solution… When you write in ink you realize that it is the concentration you’re after and not ideas. 
Improvisation is sometimes called “composition in real time”. This is projection and oversimplification, but it respects improvisation as crafted music, and may be close to the truth. It notices how quickly we can hear, react, imagine, plan, organize, deploy, and correct. Feldman brings this immediacy into notational composition with his exclusive use of ink. Denying erasure makes each written note a performance not qualitatively different from the translation of notation (or idea) into physical gesture. And if, then, the only difference between written and played “performances” is the speed at which they proceed, then composition as Feldman performs it is “improvisation in slow motion”. Feldman’s practice of notating embodies an improvisational performance, as he engages in real time with his material. His late pieces, such as palais de mari, offer repetition without pulse or predictability.  While demanding precision from the performer, they create immediacy and freedom for the composer, filtered through the concentration that his self-limiting method provides. Here’s palais de mari, played by the wonderful Aki Takahashi.
To be in one place, and no other, we must be absolutely available.
(Erik Ehn) 
Mystical disciplines like Zen begin with methodical training structures which when established become load-bearing, a stabilizing refuge for the student in the throes of disillusion. As practice deepens, structures become sites of ease and virtuosity, finally dropping away as vestigial. The masterful improviser may no longer consider her playing “practice”, just as the mature Zen practitioner does not meditate for the training or discipline of sitting, but embodies a stability and spontaneity that is at ease in any situation, sitting or not. My last example is from a great band, the Art Ensemble of Chicago. Their founder, Lester Bowie, described their performances like this:
We put a basic sketch in our minds of what we may want to do… but at the same time we don’t limit ourselves. We will play a song that we haven’t said that we were going to play, and we’ve conditioned ourselves, if something comes up, to go with it. … I mean, sometimes we go on the stage with no idea. We have what we call ‘stoop and hit,’ which means just hit. We ask, ‘Hey, what do you feel like playing?’ Nobody says anything. ‘Well, let’s just stoop and hit.’ And we go on out there with no idea what we’re going to play. 
Bowie claims that the Art Ensemble didn’t practice improvising. He describes the group rehearsing set compositions, and then using those compositions as shared vocabulary in performance, always available to be torn apart and repurposed on the spot, rarely performed whole. The performance happens in real time as the ensemble members flow through shared vocabulary, initiating and supporting in rapid alternation, rarely planned, always responsive.
Another Zen story tells of a student visiting the master on her deathbed. The student asks, “What is the teaching of an entire lifetime?” The teacher replies, “An appropriate response.” What virtuosity is actually gained through training? The virtuosity—virtue—of sensitivity: that which can respond appropriately, creatively. The Art Ensemble practiced their compositions, learning and memorizing the material not just to the point of reproducibility, but past it, to the point of fluency. The compositions are their language, and in performance they just “‘Stoop and hit,’ which means just hit”. Repetition is the practice, but appropriate response is the performance, as the improviser uses a tool that exists in time—that creates time—to gain freedom from time. Extempore. The virtuous practitioner transcends her training and renounces the easy security of planning and anticipation, creating a new space that is both empty of the known and full of possibility. She is
While the music lasts.
These are only hints and guesses,
Hints followed by guesses; and the rest
Is prayer, observance, discipline, thought and action. 
1 Morton Feldman, Give My Regards to Eighth Street (Exact Change, 2000). 28-29.
2 Theodor Stcherbatsky, Buddhist Logic, Part 1 (Kessinger, 1930). 120.
3 T.S. Eliot, Four Quartets: Dry Salvages.
4 Robin D. G. Kelley, Thelonious Monk: The Life and Times of an American Original (Simon and Schuster, 2009). 217.
5 Feldman, Give My Regards to Eighth Street. 207.
6 Morton Feldman, Palais De Mari, 1986. Universal Edition.
7 Erik Ehn, “Eschata-Logos Word and Ruin,” PAJ: A Journal of Performance and Art 31, no. 1 (2009).
8 Lester Bowie, quoted in Paul Steinbeck, ““Area by Area the Machine Unfolds”: The Improvisational Performance Practice of the Art Ensemble of Chicago,” Journal of the Society for American Music Volume 2, no. Number 3 (2008). 405, n. 38.
9 T.S. Eliot, Four Quartets: Dry Salvages.