# A Claude Code mod plays MIDI music when it works > Source: > Published: 2026-10-07 23:06:24+00:00 Important Only tested on macOS. Not sure yet how it behaves on Linux or Windows. I'm an engineer, but these days I solve the boring problems entirely by vibe coding. Somewhere along the way I felt I had lost the creativity and curiosity I used to have when writing code myself. So I started thinking about how to make vibe coding fun again. miod is the first try: while the agent does the work, you get to hear it think, read, edit, fail and fix, with a little piece of music no one has heard before. Feel free to add more moods, flavours and styles. Each mood is one row in `hooks/moods.ts`, each flavour one row in `hooks/flavours.ts`, each sound style one entry in `hooks/styles.ts`, and each wave look one file in `hooks/waves/`. Feeling it's a bit too noisy? 🙉 No hard feelings. Just [turn it off](#usage) with `/miod off`. A Claude Code mod (MIDI + mod) that writes music on the spot while Claude works. No music files, no library, no AI model. - Every task picks its own flavour (lo-fi, chiptune, ambient, jazzy and 8 more), key, scale (16 of them), chord progression, tempo, sound and theme. - The mood follows what the agent is doing. Every mood has 10 variants, and a new one is picked as the task goes: whenever the activity changes, and every 4 phrases. The task's flavour bends it too, so editing in a lo-fi task sounds nothing like editing in a chiptune one. - The faster it spends tokens, the busier the music. - Above the prompt, one line shows the mood, flavour, key, tempo and energy, with a wave under it that scrolls with the music, coloured by mood: - Tasks flow into each other: the next task fades in, in a related key. If no new task comes, a closing chord fades out at the end of the phrase. Needs Claude Code 2.1.290 or newer, on macOS. ``` claude plugin marketplace add delexw/miod claude plugin install miod@miod ``` Then start a new session. ``` /miod is it on or off? /miod off stop the music /miod on play again from the next task /miod wave list the wave looks: bars, line, mirror, dots, pulse /miod wave dots switch the wave to the dots look ``` Each row below is the mood's first variant. All 10 are in `MOODS` in `hooks/moods.ts`. | The agent is… | When it uses… | Sounds | |---|---|---| | thinking | no tool | calm | | reading | Read, Grep, Glob, MCP tools | airy | | exploring | WebSearch, WebFetch | curious (lydian) | | planning | TodoWrite, plan mode | hopeful (major pentatonic) | | asking | AskUserQuestion | waiting, almost silent | | editing | Edit, Write | bright (major) | | running | Bash | driving beat | | installing | npm, bun, pip, brew… install | patient (minor pentatonic) | | testing | test, check, lint, tsc | focused (dorian), busy beat | | shipping | git commit, push, merge, gh pr | triumphant (mixolydian) | | deleting | rm -r, git reset --hard, git clean | ominous (phrygian), low drone | | delegating | Agent | one harmony voice per subagent | | failing | a Bash command that failed | tense (minor), until a command passes | When several happen in one 8-beat phrase, the one higher in `STRONGEST_FIRST` (`hooks/activity.ts`) wins. A filling context window lifts the melody and, past 80%, adds a low drone. The scales follow how musicians describe each mode ([musical-u](https://www.musical-u.com/learn/the-many-moods-of-musical-modes/), [Jiang et al. 2024](https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2024.1414014/full)). - **Mood variant:** add a row to that mood's list in`MOODS` in`hooks/moods.ts` . - **New mood:** add the name to`Activity` and`STRONGEST_FIRST` in`hooks/activity.ts` , map tools or commands to it there, and give it a list of at least 10 variants in`MOODS` . - **Flavour:** add a row to`FLAVOURS` in`hooks/flavours.ts` . Each field nudges every mood: brighter or darker scale, busier or calmer, drums up or down, swing, bass line. - **Scale or chords:** add to`SCALES` or`PROGRESSIONS` in`hooks/theory.ts` . - **Wave look:** add a file to`hooks/waves/` that exports a`WaveLook` (how many rows, and a`draw` function), then list it in`WAVES` in`hooks/waves/index.ts` . - **Style:** add a wave function to`STYLES` in`hooks/styles.ts` . It must return values between -1 and 1. Then check it: ``` claude plugin validate . claude plugin test . ``` Run a checkout without installing it with `claude --plugin-dir `. - Only tested on macOS, where Claude Code plays the audio through `afplay` . - The sound is simple chiptune-style tones. - miod only hears the session it's loaded in.