https://opusmodus.com/forums/discover/Opusmodus Community - All ActivityenI just tried it :rewrite-lengths 't but it doesn't work! (def-score score-name (:title "twelve-tone" :key-signature 'atonal :rewrite-lengths 't :time-signature '((2 2) 4) :tempo 80) (instrument :omn test :channel 1 :sound 'gm :program 'acoustic-grand-piano)))Thu, 15 Oct 2026 13:12:11 +0000Great ! I'm very happy to inspire you. Doing GUI for Opusmodus algorithms is really cool !Thu, 15 Oct 2026 11:54:08 +0000Here's also a GUI to make the many settings easier to handle. Read the manual first, then it works. Be sure to set the paths in load.opmo and nt-gui. Thanks, @Stephane Boussuge – it was your example that showed me this was possible (with Claude)! NT-GUI-Manual-EN.pdfNT-GUI-Anleitung-DE.pdfnt-gui-en.opmoThu, 15 Oct 2026 09:06:02 +0000Hi, Can someone help me? I'm having another problem with the display of quintuplets. (setf comping4 (make-omn :pitch ass :length '(5h = = = = 5h = = = = 5h = = = = 5h = = = = 5h = = = = 5h = = = = 5h = = = = 5h = = = -5h 5h = = = = 5h = = = = 5h = = = = 5h = = = = 5h 5h 5h 5h 5h 5h 5h -5h -5h -5h) :span :length)) the problem disappears with def-score! (def-score score-name (:title "twelve-tone" :key-signature 'atonal :time-signature '((2 2) 4) :tempo 72) (instrument :omn comping4 :channel 1 :sound 'gm :program 'acoustic-grand-piano))) The problem recurs if I combine several lists (setf test (omn-to-time-signature (assemble-seq comping comping2 comping3 comping4 comping5 comping6 comping7) '(4 4))) (def-score score-name (:title "twelve-tone" :key-signature 'atonal :time-signature '((2 2) 4) :tempo 72) (instrument :omn test :channel 1 :sound 'gm :program 'acoustic-grand-piano))) exactly the same thing with septupletsThu, 15 Oct 2026 09:02:11 +0000https://opusmodus.com/forums/blogs/entry/10-creating-graphical-composition-tools-in-opusmodus-with-codex/Wed, 14 Oct 2026 19:57:42 +0000wow !Tue, 13 Oct 2026 22:12:09 +0000Thanks, you’re the pro! 😊Tue, 13 Oct 2026 21:30:46 +0000Thank you, exacly like that :-)Tue, 13 Oct 2026 21:21:52 +0000Corrections done – here’s everything as a ZIP file. Good point, thanks! I’ve added load-all.opmo: it loads all files in dependency order (and checks first that they’re all there). Set *nt-ordner* to your folder once, then evaluate the file. (nt-laden :lauf nil) loads only the setup without running. Machine Musicianship.zipTue, 13 Oct 2026 21:10:19 +0000Thank you for sharing. Good practice here would be to create a one load file to load them all - in a dependency sequence. The agents files returning an error: Error: Undefined operator pick-norepeat in form (pick-norepeat 30 (gen-integer 30 80)). you could use: (rnd-unique 30 (gen-integer 30 80)) or (rnd-sample 30 (gen-integer 30 80) :norep t) You could create a workspace folder called “Machine Musicianship”, include a workspace file along with all the relevant files, and then compress the entire folder into a ZIP archive. This would make sharing and loading everything much easier! :-)Tue, 13 Oct 2026 20:52:45 +0000Tue, 13 Oct 2026 20:01:56 +0000Machine Musicianship - A generative agent system I’d like to share a project I’ve been working on: a “non-trivial machine” for Opusmodus, after Heinz von Foerster. A trivial machine always answers the same input in the same way. A non-trivial machine has an internal state that decides how it reacts, and every input changes that state. The result is fully deterministic, yet hardly predictable. What it does Three agents (A, B, C). Each one combines a pitch agent and a rhythm agent. The pitch agent listens to the others, recognises interval patterns and builds up an internal value z. A selection rule then picks reactions on pitch, articulation and velocity, and the agent keeps developing its own material at every cell start. The rhythm agent plays an 8-bit counter (1 = note, 0 = rest), has a pulse and wanders through a small space. It reacts when it meets other agents or locks into the same pulse. In-between lanes. When neighbouring agents cross, share rhythmic ones or mirror each other, the lane between them produces events. These become two extra voices, and each lane is a small agent itself: it can rattle, play solo chords or fall silent. Form and presets. Global form states sit on top, together with presets: a few controls from 0 to 1, which can also change over time. Pitch fields. After the run, the voices can be mapped onto Xenakis-style sieves, large chords or scales. Pattern recognition always runs in the chromatic domain. Important: always evaluate the files in the correct order (see the manual, chapter 2.1): nt-kern.opmo einstellungen.opmo ab-functions.opmo tonfelder.opmo agent-a.opmo, agent-b.opmo, agent-c.opmo zwischen-ab.opmo, zwischen-bc.opmo form.opmo preset.opmo lauf.opmo partitur.opmo After a change, evaluate the changed file as a whole, then lauf.opmo and partitur.opmo again. I’ve added load-all.opmo: it loads all files in dependency order (and checks first that they’re all there). Set *nt-ordner* to your folder once, then evaluate the file. (nt-laden :lauf nil) loads only the setup without running. Everything is plain Common Lisp in a set of .opmo files: an engine you don’t touch, plus clearly structured files for the settings, the agents, the lanes, the form, the presets and the run. You plug in your own Opusmodus functions as reactions. The package includes an manual covering concept, settings, reference, troubleshooting and formulas. A note on language: function and parameter names are German, since that’s how the project grew. The comments and the manual are in English, and the manual has a glossary. Credits I developed this together with Claude (Anthropic’s AI assistant). The concept and musical decisions are mine; Claude did most of the coding and documentation, and we refined it step by step in dialogue. Free to use, open source. Use it, change it, take it apart, build your own pieces with it. If you make something with it, I’d love to hear it. Feedback, questions and bug reports are very welcome. André Machine Musicianship.zip Test_Run with 256 Fenster/Windows test_run_256.mp3Tue, 13 Oct 2026 19:40:22 +0000The Opusmodus Source Code and further documentation is now at Substack.Tue, 13 Oct 2026 16:37:03 +0000An Opusmodus Generative Composition Project — Version 2.4One of the enduring questions in my work with algorithmic composition concerns the relationship between statistical processes and musical coherence. Randomness, even when carefully constrained, does not necessarily produce music of compelling interest. The more consequential question, at least for me, is how stochastic behavior might be organized into recognizable musical situations, and how those situations might develop, interact, and transform over time. My continuing exploration of this question has led to the development of ST/4 — Stochastic Field Composition, a generative model for string quartet created in Opusmodus. The project takes inspiration from the pioneering stochastic compositions of Iannis Xenakis, particularly ST/4 and ST/10, without attempting to reconstruct their compositional procedures or imitate their musical surfaces. Instead, I am interested in extending some of the underlying ideas into a contemporary programmable environment, where statistical distributions, instrumental behavior, and larger formal relationships can become objects of compositional design. At the center of the program is the concept of the stochastic field: a musical region defined by a particular constellation of probabilities, constraints, and behavioral tendencies. Each field possesses its own characteristics of density, event duration, registral disposition, dynamics, and instrumental activity. These fields can be juxtaposed to produce contrasting musical moments, or they can gradually morph into one another, allowing their statistical properties to evolve over time. Version 2.4 introduces several important developments in this approach. A system of stochastic rubato permits event-arrival rates to accelerate and decelerate within individual fields, producing a sense of temporal breathing without relying upon conventional changes of tempo. Composer-defined rhythmic subdivisions, including tuplets, extend the available temporal vocabulary, while independently articulated instrumental ambitus trajectories allow each member of the quartet to move through, expand, or contract its available pitch register according to its own evolving contour. Of particular interest to me is the possibility of creating musical direction without prescribing individual notes or gestures in advance. An instrument might gradually ascend while narrowing its active register, while another expands downward into a more widely distributed pitch field. Simultaneously, the density of events might increase, the durations become shorter, and the collective texture move toward a more agitated state. These processes are individually programmable, yet their interaction gives rise to musical circumstances that are not entirely predetermined. This is where the distinction between control and emergence becomes especially important. The composer establishes the conditions within which the music can unfold, but the particular realization remains contingent upon the generative process. My interest is not in surrendering compositional responsibility to chance, but in discovering how carefully designed systems can produce relationships, continuities, and unexpected details that invite further listening. The implementation makes use of Opusmodus and its Constraints System, alongside procedures for stochastic event generation, temporal interpolation, and the construction of instrumental parts. The result is intended to be both a practical compositional instrument and an environment for research into the organization of musical time, texture, and form. Accompanying this post is an illustrated user guide for ST/4 version 2.4, documenting the program's architecture, composer controls, field definitions, temporal and registral transformations, and procedures for generating and evaluating musical results. I have included the guide not simply as software documentation, but as a way of making the compositional thinking behind the program more accessible to those interested in algorithmic music, stochastic processes, and the creative possibilities of Opusmodus. The project remains a work in progress for my own composition work, as I expect such investigations always will. Each new capability suggests further questions about the relationship between formal intention and perceptual result. Ultimately, the measure of success is not the sophistication of the algorithm, but whether the music that emerges from it possesses a convincing sense of identity, movement, and consequence. For me, that remains the essential task: to discover coherence through listening, and to use the algorithm not as a substitute for musical imagination, but as an extension of it. Accompanying material available at Substack: ST/4 — Stochastic Field Composition v2.4: Independent Instrumental Ambitus Morphology — Illustrated User Guide. The guide provides an overview of the program, explanations of its principal parameters, diagrams of its temporal and registral processes, and suggestions for experimentation with the generative model. Paid subscribers can download the Opusmodus program from Substack. Now available on Substack.Tue, 13 Oct 2026 16:24:15 +0000Tue, 13 Oct 2026 15:32:03 +0000The field library for the current working version ;;; Each field: name, per-instrument arrival rate per 1/16, ;;; sounding durations in 1/16 units, register center/width ;;; (normalized within each instrument's pitch field), ;;; dynamics, and per-instrument activity multipliers. ;;; An activity multiplier of 0 silences that instrument. (defparameter st4-field-library '((:suspended :rate 0.10 :durations (4 6 8 12 16) :center 0.50 :width 0.46 :dynamics (pp p mp) :roles (1.0 0.65 0.85 0.50)) (:agitated :rate 0.75 :durations (1 1 2 2 3 4) :center 0.65 :width 0.18 :dynamics (mp mf f ff) :roles (1.15 1.0 0.95 0.75)) (:fragmented :rate 0.26 :durations (1 2 3 5 8) :center 0.50 :width 0.38 :dynamics (p mp mf f) :roles (1.0 0.45 0.85 0.65)) (:saturated :rate 0.85 :durations (2 3 4 6 8) :center 0.50 :width 0.48 :dynamics (mp mf f ff) :roles (1.0 1.0 1.0 1.0)) (:residual :rate 0.08 :durations (1 1 2 3 4) :center 0.80 :width 0.17 :dynamics (pp p) :roles (0.70 0.35 0.45 0.20)))) ;;; The composer determines the form explicitly. ;;; Each entry is (field-name number-of-4/4-measures). ;;; Unequal proportions and returns are intentional. (defparameter *st4-field-form* '((:suspended 4) (:fragmented 5) (:agitated 5) (:suspended 3) (:saturated 6) (:fragmented 5) (:residual 4)));;; The composer determines the form explicitly. ;;; Each entry is (field-name number-of-4/4-measures). ;;; Unequal proportions and returns are intentional. (defparameter *st4-field-form* '((:suspended 7) (:fragmented 1) (:agitated 1) (:suspended 3) (:saturated 2) (:fragmented 1) (:residual 8)))Same seed, and all other parameters the same. Only change is the form definition above.Tue, 13 Oct 2026 14:35:06 +0000Where the algorithm is headed, generally speaking: Compositional Form Sequence, duration, proportion and recurrence of musical moments to Stochastic Field Definitions Density, duration, tessitura, register, dynamics, silence and instrumental relationships to Field Relationships and Transitions Juxtaposition, overlap, gradual morphing, interruption, recurrence to Stochastic Event Generation Independent instrumental realizations governed by the active field to Constraints and Musical Evaluation Local field identity, ensemble relationships and larger formal coherenceTue, 13 Oct 2026 13:54:41 +0000Addition: How-to/Stochastic - 4.0.32645Tue, 13 Oct 2026 07:53:20 +0000Fix to disassemble-omn: 4.0.32629Tue, 13 Oct 2026 04:22:22 +0000I need to extend the disassemble-omn functionality to cover the new nestet tuplets symbols. Will make a new build tomorrow.Mon, 12 Oct 2026 21:16:38 +0000Superb! And NOT EASY! This is so welcomed!! Bravo!Mon, 12 Oct 2026 19:56:59 +0000Oh yes, I see. Thank you for your thoughts. I certainly understand your point, and I agree that a thriving forum community depends upon the generosity of its members and their willingness to exchange ideas, experiences, and knowledge. I have always valued that kind of collegial exchange, particularly in the world of computer music, where so much of our collective progress has depended upon people sharing their discoveries. At the same time, I am trying to develop something rather more substantial through my Substack publication. After more than four decades as a professional composer, researcher, and educator, including over thirty years teaching composition and music technology at the university level, I have accumulated a considerable body of knowledge, experience, and intellectual property. I am now devoting a significant amount of my time to documenting that experience, developing original compositional software and generative models, and writing about the ideas and techniques that inform my creative practice. This is not simply a matter of sharing a few examples or fragments of code. Much of what I am publishing represents many hours, sometimes days or weeks, of research, experimentation, programming, testing, musical evaluation, and documentation. I regard this work as an extension of my professional creative practice, and I believe that both the intellectual effort and the time invested in it have value. My Substack is intended to provide a sustainable way of continuing this work, with freely accessible writing alongside more substantial materials available to supporting subscribers. The modest subscription fees are a means of supporting the ongoing research and development, rather than an attempt to discourage the exchange of ideas. I remain very happy to participate in the forum, share insights, discuss techniques, and contribute to the community. Indeed, I hope that what I am doing will ultimately enrich that community as well. But I also believe that composers, researchers, and educators should feel comfortable assigning value to their intellectual and creative labor, just as we recognize the value of the software and other tools we use, such as Opusmodus. I hope you can appreciate the distinction. I see these two forms of engagement as complementary rather than competing, and I would very much like to continue contributing to both.Mon, 12 Oct 2026 19:50:34 +0000I think it’s much better for the forum community and engagement if you post it here directly rather than referring people to your website. In my opinion it’s more direct and helps the forum community thrive ☺️Mon, 12 Oct 2026 19:38:39 +0000Yes, the audio example was created using Opusmodus and the current program version is v1.8.1 - basically it creates a continuous stochastic morphology and uses some of the new constraints functions that have recently been added to Opusmodus. I used the VSTi Opus, a sampled string quartet, and recorded the example with Nuendo. I do plan to share this program when I am finished working on it. The Opusmodus program and reference materials will uploaded to my Substack.Mon, 12 Oct 2026 19:37:27 +0000I know the Xenakis things. I thought you had programmed your track/example in Opusmodus, so the code would be easy to share.Mon, 12 Oct 2026 19:28:31 +0000