I am not qualified to write about The Harp of New Albion.

The Harp of New Albion is a piano recording by Terry Riley, released in 1986, the year of my birth. Tracy and I have an argument about whose birth year is better: I have The Legend of Zelda, she has Super Mario Bros. (1985). I've got The Harp of New Albion. Does this make me the winner?

I am not qualified to write about The Harp of New Albion, which is, from what I can glean, the sort of technical and artistic accomplishment you would expect from the author of In C. All I know is it's beautiful and absorbing:

Wikipedia tells me it was written in "just intonation." What is just intonation? Well:

In music, just intonation (sometimes abbreviated as JI) is any musical tuning in which the frequencies of notes are related by ratios of smallwhole numbers. Any interval tuned in this way is called a just interval. The two notes in any just interval are members of the same harmonic series.^[1] Arbitrary frequency ratios such as 1024:927 are not generally said to be justly tuned.

Just intonation can be contrasted and compared with equal temperament, which dominates Western orchestras and default MIDI tuning. In equal temperament, all notes are defined as multiples of the same basic interval. Two notes separated by the same number of steps always have exactly the same frequency ratio. However, except for doubled frequencies (octaves), no other intervals are exact ratios of integers. Each just interval deviates a different amount from its nearest equally tempered interval.

Justly tuned intervals are either ratios, with a colon (for example, 3:2), or as fractions, with a solidus (3 ⁄ 2). For example, two tones, one at 300Hertz (cycles per second), and the other at 200 hertz are both multiples of 100 Hz and as such members of the harmonic series built on 100 Hz.

I hope that clears it up for you. I'll admit it's not much help to me. This part I get a little better:

Some composers deliberately use these wolf intervals and other dissonant intervals as a way to expand the tone color palette of a piece of music. For example, the extended piano pieces "The Well-Tuned Piano" by LaMonte Young, and "The Harp Of New Albion" by Terry Riley use a combination of very consonant and dissonant intervals for musical effect.

As (I think) in "Circle of Wolves," which does not appear to be available for streaming.

Kevin Holm Hudson says yes! It's true!

As a result of Riley’s just intonation tuning, three “fifths” are identifiable as so-called “wolf fifths” - 40/27 (D#-A# and E-B) and 1024/675 (B#-G). It was the “out of tune” quality of these intervals that led to certain keys historically being considered unsuitable for modulation. (Figures 3 and 4 show how strikingly different such intervals are from the “pure” just-intonation ratio of 3/2.) Of these “wolf fifths,” the most complex (therefore “out of tune”) ratio is 1024/675, heard in this tuning only between the pitch classes B# (C) and G. As a result, B-sharp - the tonal center of “Circle of Wolves” - is the key “most distant” from the C-sharp tuning center. The B-sharp/G dyad (or C-G) makes up the tonic and “fifth” scale degree of the pitch collection that characterizes “Circle of Wolves”; the other pitches in the collection are the two 40/27 fifths. The resulting sonority is as “out of tune” as possible within the tuning system, and Riley explores its unusual quality deliberately by making it the main sonority of his improvisation (Example 1).  The title is a punning reference not only to the “wolf” quality of these fifths but to the classical “circle of fifths” that results from equal temperament.

Kevin Holm-Hudson writes:

Then Riley returned to the piano. As he related in an interview, “Around 1980 I bought an old upright and started to play and develop music on piano again. Of course, I’d been aware of La Monte [Young]’s Well-Tuned Piano since ’64, but I’d also been playing both Indian music and electronic keyboards in just intonation. So I decided to tune the piano that way rather than in equal temperament.” Because of the way that the overtones of piano strings resonate sympathetically with other strings, working in just intonation turned out to be a powerful expressive tool for Riley: “I was able to give the music a different shape. The piano has a much greater scope of expressive possibilities than electronic instruments.”

That's a good way of explaining why the sound of Harp is so rich! Nice. Wish I had thought to put it that way.

Not sure who wrote this, but it also helps:

Although Riley improvises throughout The Harp of New Albion, each movement is defined by structural or composed elements. Astonishingly, the halo of harmonics drifting above his solo piano creates an orchestral sound, complete with horns, reeds, strings and voices. At times, the melodic interplay is ethereal, the micro-tonal relationships within the standing waves of sounds creating a haunting spectrum.

Is that what it's called? A halo? Is this a technical term? It's possible, in listening to the album, to imagine it was recorded using much more than one piano, is the point: the harmonics are so rich as to allow the listener to participate in a unique, surprising way, weaving melodies and harmonies and accents from the air, from suggestions of those things left like ghosts on the air. The things you hear are there and not there: you choose them, interpret them into their fullness. The way that in a sufficiently large crowd or in the midst of sufficiently resonant white noise you can hear music or language where there is none. See for instance:

The note is struck and then it radiates outward from that instance, its impression growing larger than its occasion.

More from Holm-Hudson:

Another aspect of Indian classical music, all the more striking in Riley’s case because it is found in Indian vocal (rather than instrumental) style, is a technique of ornamentation called gamak. Peter Manuel describes gamak as “a technique in which every note in a passage is approached from its lower neighbor,” and notes that the practice has “crossed over” from Indian classical music to popular genres such as film music. Riley’s improvised passages in “Magic Knot Waltz,” especially the long rhapsodic lines that come at cadential points, employ the same “lower neighbor” ascending-step contour cited by Manuel as essential to gamak. One example of this technique in Riley’s improvisational style is found in Example 5.

You know this explains a lot about the quality of the sound that I couldn't have explained myself! The simultaneous fluidity and angularity of it.

In listening to the music one suspects it was improvised but it seems so deliberate. The logic or the arc of the improvisation is sufficiently clear -- at least in the broad sense of its trajectory -- that the listener can follow it. And yet it must be composed to some extent, as the logic takes sudden sharp turns no one could think of on the spot, and the system of the music is too perfect for an accident, the notes of a whole even in their sourness or "falseness." Holm-Hudson explains:

The goal of tightly structured improvisation is evident throughout The Harp of New Albion. Much of the work is improvised, but improvised passages are found side-by-side with composed ideas. A performance of a movement from The Harp of New Albion can perhaps be compared to a jazz improvisation, in which the theme or “head” is followed by solos over the chord structure before concluding with a return to the “head.” The interchange between “composed” and “improvised,” however, is much more fluid in Riley’s music; John Schaefer describes the piece as having a “spiral form.” As Riley explains it, “Something spins off a little motif and gets larger and more arpeggiated, more embroidered. It cycles back to a certain note, but it’s very irregular; it takes a circuitous route.”

The results are in some ways my ideal of an artistic object. The Harp of New Albion takes absolute responsibility for its own beauty. It was recorded with care, after extensive thought and planning, on a piano perfect for the task. It was composed to the extent that composition would make it beautiful. Then, Riley sat down and played, improvising to the extent that his improvisation would make the recording beautiful. The object is the result of a successful negotiation of several competing impulses, including an urge toward timelessness (the seemingly infinite deliberation made possible by composition in advance) and an urge toward timeliness (the practical necessities of performance, of improvisation, of music as a thing happening now). This is more or less how I try to write a book, with allowances for further cycles of composition (revision, control) and improvisation (exploration of new possibilities in the text).

What I mean is when I read I like to feel the thing was written, and the weight and the arc of its writing, in addition to enjoying the contents. There are quite a few things that seem to be errors in Infinite Jest but which also illuminate the novel's composition; there are passages gorgeous in their apparent improvisation. 

I try to avoid the fallacies and self-loathing implications of identifying my writing with music too often, but I would like my novels to feel often, as much as possible, like The Harp of New Albion.