Show HN: What if your synthesizer was powered by APL (or a dumb K clone)? (octetta.github.io)

by octetta 33 comments 92 points
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33 comments

[−] jodrellblank 62d ago
Marshall Lochbaum's APL-derived language BQN has some nods towards audio synthesis too:

https://mlochbaum.github.io/BQN-Musician/synth/index.html

[−] octetta 62d ago
BQN kicks-ass and I've spent hours listening to the Array Cast podcast while in SoCal traffic. I'll check his stuff out with an eye towards the audio stuff.

I'm an APL newb... while I've been writing code-for-cash forever (C, etc.) I've had a long-time interest in APL languages, but I'm just messing around after working on waveform generation for another sound project I have in the works (https://github.com/octetta/skred ... https://youtu.be/L5-3gBpJsAo?si=JdBlntzn4doY-c3s).

While I was working on this I remember the first book I saw in the public library on computer programming was about APL (probably sometime around 1976)... I didn't have access to a "real computer" for another year after that and no APL for decades, but some ideas stick around, LOL.

[−] bradrn 62d ago
[−] octetta 62d ago
Wowie! I'M NOT WORTHY! Cool stuff!
[−] bradrn 62d ago
It’s not my language, to be clear! In fact I’ve never even tried it… my array programming experience so far has mostly been with J.
[−] octetta 62d ago
Doesn't matter. Just happy people are doing weird stuff like this and appreciate the share. I looked at a bunch of APL-ish implementations and kind of ran with the K-simple code (links on the repo). What background do you come to J from? Another programming language? How do you like it?
[−] bradrn 62d ago

> What background do you come to J from? Another programming language?

Yes, I’m very fond of trying out different languages. My main language for personal projects is Haskell.

> How do you like it?

I haven’t used J for a while, actually, but I recall finding it a bit confusing, especially when rank manipuations are involved. It has a larger vocabulary than most array languages, which I felt made it hard to learn. It was great fun though!

[−] octetta 62d ago
Fun. I've lost count of the languages I've learned and gotten paid to use over the years, but it's mostly very exciting to add a new one to the list.

Haskell is one I haven't used yet. The closest I've come to that is a weekend fling with OCaml... much respect for the ML work though!

I hear you for the complexities in J though. I've intentionally limited k-synth to single letter upper case variables and the verbs are also one character... I might regret this at some point.

Have fun! It makes the world a better place!

[−] jart 62d ago
How do we get it to play Kompressor? https://youtu.be/9tlA0IyKjiI
[−] octetta 62d ago
Wowie... Jart commented! I'm on it my friend. Certainly sequencing is a good thing to add.
[−] UncleEntity 62d ago

> ...and the right-to-left evaluation logic.

The evaluation order doesn't matter as much as you don't really know what kind of function/operator you have at parse time so have to do a bunch of shenanigans to defer that decision until runtime while still keeping it efficient. Kind of fiddly to get right but once it works, it just works.

Claude and me (and a ton of decades old research) pretty much figured out all the complications in the APL parse/eval stack (https://github.com/dan-eicher/AiPL).

[−] octetta 62d ago
I'm looking forward to checking out your stuff...
[−] octetta 62d ago
I have a CLI and desktop versions on github (all MIT license)

https://github.com/octetta/k-synth https://github.com/octetta/ksynth-desktop/

it's been a blast to play with... and a great excuse to learn array languages

[−] octetta 62d ago
A warning... if you save a setup to JSON, it naively stores the generated waveforms put in slots and the notebook, so the files can become quiet large. I have a plan to just keep the code behind the waves and regenerate the waveforms at load time.
[−] octetta 62d ago
On the C-side, I'm going to add a UDP listener to the code so I can send k-synth incantations live from Emacs (something I did for my skred program at the suggestion of an Emacs user). Let me know if anyone wants to know about this when it's usable. On the desktop app side, I use miniaudio (thank's Macron) so this is portable to the usual suspects. I also made a single header file cross platform midi library which I have some devious plans for in this space. Stay tuned.
[−] hmokiguess 62d ago
Pretty cool, one suggestion for the site would be to have templates you can quickly load, copy, edit, and share. Sort of like strudel.cc has!
[−] octetta 62d ago
i wimped out and just have the patches being loaded from my github repo. good suggestion though.
[−] xrd 62d ago
Did you know you can embed strudel?

https://strudel.cc/technical-manual/project-start/

[−] hmokiguess 62d ago
I don’t think this is relevant to my analogy there, what were you thinking here?
[−] xrd 62d ago
You are right but I wondered if octetta had considered combining his ui with strudel. I am fascinated by it and have been attempting to riff off it and create new creative interfaces.
[−] octetta 62d ago
I'll take a look... it's probably not obvious, but the language engine is actually written in C and emscripten-ed to WASM, so I've already crossed several bridges to get this done. Absolutely riff off this interface... would love to see what you can make. My stuff is MIT licensed, so tear it up! On a side note, I was able to meet Sam Aaron of SonicPi / Tau5 at Goarmire back in September which was cool... he teased us with Super Collider in JS then and since, he's crossed the finish line on that stuff. We live in amazing times! Have fun!!!
[−] xrd 62d ago
That's a great story. It's beautiful you are building on the shoulders of giants and putting it out there for others to build upon. Very exciting times, indeed!
[−] octetta 62d ago
Strudel (and PureData, and ChucK, and SuperCollider, and AMY) are all great projects, but they weren't scratching my itch, so after I got laid off from a FAANG role, I rage/anxiety started writing code for stuff fun-ner than writing code for radios and routers and satellites... this is where my cortisol / dopamine lead me. No disrespect to those other projects... all have been inspirational and are a heck of a lot more "respectable" than my playground code.
[−] octetta 62d ago
At any rate, in case it's hard to see, definitely try loading the dm-bell.ks patch, putting it in slot one so the melodic pad can play it... it's quick and dirty to see what's capable in a few keystrokes... although I'm sure the PD and ChucK and SC and ... wizards could put me to shame in a showdown, LOL.
[−] octetta 57d ago
Many updates... if you're still watching this, try it out here:

https://octetta.github.io/k-synth

[−] swaminarayan 61d ago
Could a K-style array language be a practical way to design audio waveforms and DSP patches?
[−] octetta 61d ago
that's what i'm playing with... thoughts?
[−] octetta 60d ago
It might not be obvious (and doesn’t work on my iPhone or iPad), but if you right click on pads with sounds loaded, you can mess with the pitch of sounds, rename them, and download a wav file for use elsewhere.
[−] octetta 61d ago
I fixed a few broken examples in the README.md file but I don't have the related readme.html file used in the web app getting automatically updated, so they're out of sync at the moment.
[−] jdontillman 62d ago
See also: Stanley Jordan, "APL For Music".

https://dl.acm.org/doi/pdf/10.1145/75144.75174

(!!!)

(Wait, what? That Stanley Jordan?) (Yep.)

[−] octetta 62d ago
Wow! I had no idea, will look here for inspiration too. Thanks!
[−] steveBK123 62d ago
This is great
[−] octetta 62d ago
thanks!
[−] stainlu 62d ago
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[−] useftmly 62d ago
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