Nathan Ho (Posts about electronic music)

Nathan Ho - Steganography

Nathan Ho — Mon, 11 May 2026 05:00:00 GMT

Steganography is my second album. Eleven tracks, 30 minutes. Fully synthesized. Distributed by 3OP. Digital download on Bandcamp.

Vertex Figurine
Growing Plums in the Desert
Why Becoming Selfish is the Best Thing I Ever Did
Unmaker Process
Despite Our Best Efforts
Warring Factions
Irreversible Information Acquisition
Things Toxic Friends Say
Systematic Instinct
Stab Variation
Treachery

Mastering by Nil Hartman.

Available as a hand-bound 250-page hardcover book containing the complete SuperCollider source code to the album. A hole cut in it contains a USB stick with 48k/24 audio files. Limited run of five books. I am making them all by hand. (I may make another batch if they sell out, but no promises!)

The source code is not available digitally. These books are the only place to get it.

Lime68k & Nathan Ho - Striations of Grace

Nathan Ho — Tue, 30 Sep 2025 15:23:17 GMT

Striations of Grace, a collaborative album on by Lime68k and me, has been announced on EVEL Records, releasing October 3rd on digital, CD, and a 7” vinyl edition. Seven tracks, 53 minutes of cosmic horror synthesis mutations.

Lime68k & Nathan Ho - SOLVE
Nathan Ho - The Kraken
Lime68k - Out to Own Concern
Lime68k & Nathan Ho - We Regret the Error I
Lime68k - Who’s Out Concerns [vinyl release side A]
Nathan Ho - Exterior Algebra and Heroin [vinyl release side B]
Lime68k & Nathan Ho - We Regret the Error II

Lime68k used Max/MSP, I used SuperCollider. One year in the making.

Mastering by Alfonso. Cover art by Aplauso.

Cybernetic Synthesis and Roland Kayn

Nathan Ho — Wed, 20 Dec 2023 00:41:04 GMT

Let’s open this post with music. If you aren’t familiar with the late composer Roland Kayn’s work, listen to one of his Electronic Symphonies, or at least sample a few minutes. The album cover links to his official Bandcamp.

I found out about Kayn’s music through a thread on Lines, and it gets only more interesting as I looked into his story. Kayn was an exponent of combining music with cybernetics, a field I gloss as “the study of feedback systems.” At its heart, it’s a mathematical study; Norbert Wiener’s original text Cybernetics is chock full of integrals and differential equations. As the field developed, it overlapped significantly with medicine, social sciences, humanities, and especially critical theory. I do hope to read Wiener’s Cybernetics and The Human Use of Human Beings, but haven’t gotten around to them, so consider my understanding of the field surface-level — I’m mainly concerned with cybernetics as it relates to Kayn’s music.

Kayn began making cybernetics-influenced electronic works in university electronic music studios in the 60’s. We don’t know what exact tools, but Pickles’ 2016 dissertation Cybernetics in music surmises that the equipment back then was something along the lines of tape machines and basic analog processors and generators: oscillators, noise, filters, reverbs, envelope generators, ring modulators. More intriguingly, recordings of his works were entirely real time — a stark contrast to the offline tape-based processes of the contemporary musique concrète movement. Critic Frans van Rossum wrote in 2011 that Kayn worked with a “network of electronic equipment” and a “a system of signals or commands that it can obey and execute” (quote also via Pickles).

EDIT 2023-12-20: An earlier version of this post credited the technology to Kayn alone, but I have since been properly schooled: it was Jaap Vink who actually built the system, as Sascha Frere-Jones wrote in 4Columns. Given the intimacy that cybernetic musicians necessarily have with their tools, his fingerprints are deeply embedded in Kayn’s electronic works. The sources I looked at didn’t make this clear to me, and most don’t even mention Vink by name. Vink referred to himself as a technician, not a composer, and it’s possible that the concealment of his status was his preference.

That these works were likely made on 60’s equipment, were recorded in real time, and sound varied and dynamic over long stretches of time should impress anyone familiar with modular synths. The implications that his musical systems had some kinds of self-generating and autonomous properties makes this even more remarkable. Now Kayn’s output is more than just great music, it’s now a puzzle. How did he make this music? Can we recreate part of his process?

I don’t think we’ll ever get definitive answers. Kayn died in 2011, Vink in January 2023. While there’s a small body of writing about them, little of it is technical. We can only guess, but we have some resources that helps us with the guessing process — the Lines thread I mentioned, and also La Synthèse Humaine, a YouTube channel run by musician Émile Zener a.k.a. Gunnar Haslam. He takes direct inspiration from Kayn, and unlike me has extensively studied the cybernetics literature. I won’t take the time to resummarize the Lines thread or Zener’s work — just go check them out for yourself — instead I am interested in expanding on them.

Making a cybernetic LFO

It’s perhaps easiest if I first walk you through a concrete example of building a cybernetic patch. We begin with the simple harmonic oscillator, which can be implemented with the system of ordinary differential equations

\begin{equation*} \begin{align*} \dot{a} &= -kb \\ \dot{b} &= ka \\ \end{align*} \end{equation*}

and the following block diagram:

This comprises two integrator stages in a feedback loop. An integrator is a unit that continuously accumulates the input signal (you can get something like a leaky integrator with a one-pole lowpass filter with a very low cutoff). The triangles are simple amplifiers multiplying by constants; one must be negative and the other positive. There are two outputs, A and B, which produce a sine and cosine wave respectively. The system does need an initial “kick” to generate sine waves, by e.g. initially setting \(a(0) = 1\) and \(b(0) = 0\).

Assume that the oscillator is tuned to oscillate at a slow 1 Hz. It is an “LFO” in the literal sense that it oscillates at a low frequency, but critically we aren’t generating it with an actual oscillator module, and the oscillation is an emergent property of the system that we built. We can turn this into an audible synthesis patch by using the two outputs, A and B, as amplitudes, multiplying them with VCAs by two saw oscillators with static frequencies. Mixing the oscillators together, we have a simple looping alternation between two “notes” even though we have no actual sequencer here.

However, the oscillators and VCA’s aren’t part of a loop, and their output does not influence the rest of the system. For reasons that I’ll justify later, we loop in their VCAs by running an envelope follower on the output of the VCAs, and using it to modulate the coefficients of other VCAs that are in the loop.

(I’m misusing notation here a bit; the arrows into the loop VCAs are not actually setting the gain, but wiggling around the gain it had in the previous diagram. The intentions of this diagram are more romantic than schematic — the point is to illustrate the closing of loops, not to specify an exact algorithm.)

This isn’t an actual simple harmonic oscillator anymore, but it mimics the core behavior of one. However, if we start changing any parameter, the core behavior of the “LFO” starts changing too. Everything interacts with everything, and nothing is isolated or purely upstream or purely downstream.

We’ll return to this patch and expand it into something more compelling in sound design terms. Let’s go theoretical for a bit and explain what we’re actually trying to do here.

Nathan Ho - Haywire Frontier

Nathan Ho — Sun, 03 Sep 2023 00:57:37 GMT

My first full-length solo album, Haywire Frontier, is releasing on Saturday, September 9th on the Japanese label Tokinogake. It is available for preorder now, and you can listen to the opening track “Trickster Deity.”

Here are the liner notes:

In 2008, at the age of 11, I created Googology Wiki on my parents’ computer. “Googology” is word for the study of large numbers and fast-growing functions, deriving from the 9-year-old Milton Sirotta’s coinage of the term “googol.” The website was never meant to go beyond my personal use, and I gradually drifted away from it. Fifteen years later, it has grown to tens of thousands of articles and a community of hundreds of active users.

Haywire Frontier is a 40-minute musical tribute to a strange corner of amateur mathematics whose growth I somewhat-inadvertently catalyzed, with rhythmic and formal material deriving from Georg Cantor’s “ordinal number” system, integral to the study of large numbers.

The album was sequenced and synthesized entirely in SuperCollider with no samples, external hardware, or third-party plugins.

Credits:

John Tejada, mastering
Isa Hanssen (Instagram), cover art
Special thanks to a0n0, Charlie Burgin (Sahy Uhns), William Fields, RM Francis, Joonas Siren (Forces), Ben Tillotson, Nathan Turczan.

I expect to write about this project in the near future. Thank you for listening, and for all your support.

The Duration Trick

Nathan Ho — Wed, 05 Jul 2023 02:05:56 GMT

The Duration Trick is something I was egotistical enough to believe I discovered, but after a recent conversation with William Fields (a musical hero of mine) I have learned that I’m in no way the first to come across it. Both Fields and the Max/MSP Shop Boys have been using something like this for a while, I’m told. Learning about this case of convergent evolution spurred me to bump up this already-planned post in the queue.

Simply put, the Duration Trick is when a synthesizer patch with discrete note on/off events is given advance notice of the duration of each note. Thus, if the sequencer is modeled as sending messages to a synthesizer:

Every “note on” message is accompanied with an anticipated duration.

It’s possible for such a patch to exactly anticipate the ending of the note, so note offs don’t even need to be transmitted, although I like to give the option to cut off the note prematurely. Additionally, duration can function as a velocity-like parameter that impacts other synthesis parameters such as amplitude or brightness, so short and long notes differ in more ways than just timing.

Imagine a monophonic subtractive synthesis patch with a lowpass filter that gradually opens for each note on. Traditionally, the lowpass filter’s trajectory is independent of the note duration, and may run its course or be cut short:

With duration information, it’s possible to guarantee that the lowpass filter reaches a precise goal at the end of each note:

I find the second example slightly more exciting in this simple demonstration. For a more complex example, jump about an hour into a video session I uploaded in May. The Duration Trick may sound like a small change at first, but it had a pretty radical impact on my music and sound design when I started using it. It shines especially for transitional sweeps that need to arrive right on time. Arguably, anyone who drags a reverse cymbal sample leading up to a drop is in a sense using the Duration Trick.

Note off events in MIDI can arrive at any time, so the Duration Trick isn’t achievable with standard traditional synthesizer hardware in the absence of some CC-based hack. (This is one of many reasons that pigeonholing everything into MIDI events has had long-term negative effects on music tech, but I digress.) The Duration Trick is therefore easiest to implement in one of the “nerd” music software environments like Csound, SuperCollider, etc., particularly anything that permits scripting. The trick is possible in a real-time context, but the sequencer must of course be able to look ahead far enough to know the durations at all, so it’s more semi-real-time than fully real-time. Durations are always available for music sequenced offline, and are generally available in algorithmic composition as well.

Musicians who play or sing melodies generally don’t think in individual note ons and offs, but rather phrases and gestures if not something higher-level. Even the most reactive and on-the-fly improvisations often require calculating at a few notes ahead, and this will impact subtleties of playing style. The Duration Trick alone doesn’t capture the complexities of musicians playing acoustic instruments, but it still appears to be a valuable stepping stone to breathing some more life into a synth patch.

Correlated Granular Synthesis

Nathan Ho — Sun, 04 Jun 2023 19:00:00 GMT

Decades after Curtis Roads’ Microsound, granular synthesis is making appearances here and there in the commercial plugin market. While it’s nice to see a wider audience for left-field sound design, I have my quibbles with some of the products out there. From what I’ve heard, so many of these products’ demos are covered in reverb in obvious compensation for something, showing that the plugins seem most suited for background textures and transitional moments. In place of sound, the developers seem to prioritize graphics — does watching 3D particles fly around in a physics simulation inspire the process of music production, or distract from it?

Finally, and most importantly, so many granular “synths” are in fact samplers based on buffer playback. The resulting sound is highly dependent on the sampled source, almost more so than the granular transformations. Sample-based granular (including sampling live input such as in Ableton Live’s Grain Delay) is fun and I’ve done it, but in many ways it’s become the default approach to granular. This leaves you and me, the sound design obsessives, with an opportunity to explore an underutilized alternative to sampled grains: synthesized grains.

This post introduces a possibly novel approach to granular synthesis that I call Correlated Granular Synthesis. The intent is specifically to design an approach to granular that can produce musical results with synthesized grains. Sample-based granular can also serve as a backend, but the idea is to work with the inherent “unflattering” quality of pure synthesis instead of piggybacking off the timbres baked into the average sample.

Correlated Granular Synthesis is well suited for randomization in algorithmic music context. Here’s a random sequence of grain clouds generated with this method:

A Preliminary Theory of Sound Design

Nathan Ho — Thu, 25 May 2023 06:48:56 GMT

This post is my attempt at explaining my own philosophy of sound design. It’s not in final form, and subject to amendment in the future.

The type of sound design I refer to is specific to my own practice: the creation of sounds for electronic music, especially experimental music, and especially music produced using pure synthesis as opposed to recorded or sampled sound. These ideas presented might have broader applications, but I have no delusions that they’re in any way universal.

The theory I expound on isn’t in the form of constraints or value judgements, but rather a set of traits. Some are general, some specific, and my hope is that considering how a sound or a piece relates to these traits will take me (and possibly you) in some directions not otherwise considered. Some of the traits contain assertions like “if your sound does X, your audience will feel Y,” which in a composition may be employed directly, carefully avoided, or deconstructed. You’ll also note that the theory is concerned mostly with the final product and its impact on the listener, not so much the compositional or technical process. (Friends and collaborators are well aware that I use highly idiosyncratic and constrained processes, but those are less about creating music and more about “creating creating music.”)

No theory of sound design will replace actually working on sound design. Sound design isn’t a spectator sport, nor a cerebral exercise, and it has to be practiced regularly like a musical instrument. Reading this post alone is unlikely to make you a better sound designer, but if it’s a useful supplement to time spent in the studio, I’d consider this work of writing a success.

I will deliberately avoid talking about the topics of melody, harmony, counterpoint, consonance vs. dissonance, and tuning systems, and I’ll only talk about rhythm abstractly. There are many existing resources dedicated to these topics in a wide variety of musical cultures.

Opinionated Advice for SuperCollider Beginners

Nathan Ho — Thu, 16 Mar 2023 22:15:16 GMT

I’m often asked where to find the best resources for learning SuperCollider. My informed and professional answer, which comes from over a decade of experience with this software as a user, developer, and educator, is as follows:

I’m not really sure?

The landscape of SC learning materials has changed a lot since I started in 2012/13. I’ve heard good things about Eli Fieldsteel’s video tutorials and Bruno Ruviaro’s “A Gentle Introduction” ebook, so I guess check those out. I haven’t perused their tutorials at length, but Eli and Bruno are both seasoned professionals at SC education, so you can’t really go wrong there. Also, I have my own SuperCollider Tips blog post (which I have just updated today), which is not a structured tutorial but addresses common beginner problems. But ultimately, the most efficient learning strategy really depends on what you intend to make, because the applications for SC are so diverse, as are the backgrounds of users coming to SC.

That’s probably not too enlightening. However, I do have a lot of advice for beginning SC users, drawing from my own tortuous path through learning to make electronic music.

What follows are a bunch of guidelines that I recommend beginning SC users follow, or at least consider. A good number of them are specific to my idiosyncratic approach to SC, which I’ve expounded on in my YouTube presence: heavy focus on sound design through synthesis, and only sporadic use of hardware and real-time interaction. Also, although some of my advice may help live coders, I’m pretty uninterested in live coding myself, so I can’t give specific advice there (creative coding I’m all for, but when I share my screen it’s for education, not seamless performance art).

Interstate Hydra - Nocturnes

Nathan Ho — Mon, 16 Jan 2023 08:00:00 GMT

Exactly three years ago I made an ambient EP under the name “Interstate Hydra” and put it up on Bandcamp. Up until now I have kept this alias a secret and only shown these tunes to a few people, but I figured it’s been long enough.

Nocturnes was made entirely in Audacity using the “sound dumplings” method described in an earlier post. This was a total 180 from my usual workflow, which is to synthesize everything with SuperCollider code.

“For Ellie” is a single released months after Nocturnes, and is formally the simplest Interstate Hydra track, comprising a row of sound dumplings in arch form.

I don’t plan on returning to the Interstate Hydra alias for quite some time, but I hope you enjoy these tracks. Thank you for listening.

A Closer Look at Clarence Barlow's ISIS

Nathan Ho — Sun, 15 Jan 2023 22:37:23 GMT

In 2005, Clarence Barlow published a paper on Intra-Samplar Interpolating Sinusoids (ISIS), an audio analysis-synthesis algorithm. It did not make much of a splash, with the paper having only 7 citations in Google Scholar. Nevertheless, it produces some interesting sounds, so let’s dive into it.

First, some context. The precursor to ISIS is a technique Barlow calls spectastics. In this method, the short-time Fourier transform is computed of an audio signal, and at each frame, the magnitude spectrum is resampled logarithmically to 12EDO and used as a probability distribution to select a pitch. The pitch sequence forms an extremely rapid melody, which can be synthesized or played on a robotic instrument. Barlow describes the spectasized melody as “remarkably like the original sound recording.”

In ISIS, this concept is taken to an extreme by making the “melody” a constant amplitude sine wave whose frequency is changed every sample. Given a digital signal that doesn’t exceed ±1, we can interpolate between any two successive samples with a partial cycle of a sine wave. An image helps here; the dots show the sampled digital signal.

For example, if the samples are 0 and 1, as seen in the first two samples in the image, we can interpolate with a quarter sine wave with a period of 4 samples and a frequency of 1/4th the sample rate. There are actually infinitely many ways to do this interpolation. For example, from 0 to 1 we can also have a sine wave that completes 5/4ths of a cycle. We can even assume that the initial phase of the sine wave is \(\pi\) and the final phase \(5\pi/2\), or have the sine wave going backwards with phase ramping from 0 to \(-3\pi/2\).

To resolve the ambiguity, ISIS restricts the frequency to be always nonnegative so the phase never goes backward, and always assumes the phase at every sample point is in the range \([-\pi/2, \pi/2]\) modulo \(2\pi\). There are other approaches, such as picking the minimum possible nonnegative frequency or the frequency of minimum absolute value, which may produce interesting alternative sounds. I won’t get into these (this is a relatively low-effort post), but feel free to try them out.