What is composing-with-oscine?

Instructions for using the Oscine browser music composer to create and edit tracks, notes, drum patterns, instruments, and playback.

Use them to compose songs, beats, melodies, basslines, chords, drum parts, and synth sounds in Oscine.

They explain how musical data is represented so an AI can make precise changes in the live composer.

composing-with-oscine — Skill for Claude Code by chazmaniandinkle

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add chazmaniandinkle/oscine --skill composing-with-oscine

Clone the repo

git clone --depth 1 https://github.com/chazmaniandinkle/oscine

Made for: Claude Code.

Or install oscine, the plugin that ships this one along with the rest of its 1 skill, 1 MCP server.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/chazmaniandinkle/oscine/composing-with-oscine/github.svg)](https://agentmods.dev/skills/chazmaniandinkle/oscine/composing-with-oscine)

Your own site

<a href="https://agentmods.dev/skills/chazmaniandinkle/oscine/composing-with-oscine"><img src="https://agentmods.dev/badge/skills/chazmaniandinkle/oscine/composing-with-oscine/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/chazmaniandinkle/oscine/composing-with-oscine"><img src="https://agentmods.dev/badge/skills/chazmaniandinkle/oscine/composing-with-oscine.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 93 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,918 The whole file, excluding the scripts and references it only reads on demand.

Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00093	$0.01918
Opus 5.5	$0.00037	$0.00767
Sonnet 5.5	$0.00019	$0.00384
Haiku 4.5	$0.00009	$0.00192

Measured 1mo ago against content hash 8f9b6d27da63, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

composing-with-oscine scanned grade B with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Subtle steeringmediumPrompt injection

Instructions that bias recommendations or shape behaviour without the user noticing.

- If a tool errors with "Oscine isn't open", use `oscine_open_app` — never tell the user it failed without trying that first.

plugin/skills/composing-with-oscine/SKILL.md · 53 lines

How it starts

The opening of the file, as written. The whole thing — 53 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Composing with Oscine

Oscine is a live browser app. Tools act on the user's actual session: they hear results immediately and see every edit land in the UI.

Session start

oscine_status — if appConnected: false, call oscine_open_app, then re-check.
Audio unlock: browsers mute Web Audio until the user interacts once with the tab. If audioState is not running, ask the user to click anywhere in the Oscine tab.
oscine_list_instruments before creating tracks or setting params — it returns every param key, range, preset, and drum lane id.

Data conventions

Time is in beats (quarter notes). A slot loops bars * 4 beats. 16th note = 0.25 beats.
Pitch is MIDI (60 = C4, 69 = A4 = 440Hz). Velocity 0-1.
Drum lanes are 16th-step velocity arrays: 1 bar = 16 values, 2 bars = 32. [1,0,0,0, 0,0,0,0, 1,0,0,0, 0,0,0,0] is kick on beats 1 and 3.
Tracks are addressed by name ("Bass") or id. Slots are 'A'-'D'.

Composing workflow

Keep notes inside the loop: check bars from oscine_get_notes/oscine_slots list first, or set length with oscine_slots set_bars.
oscine_set_notes mode:replace is the main composing move — write whole patterns, not note-by-note edits.
Vary velocity (0.5-1.0) and note lengths; straight max-velocity grids sound mechanical. A little swing (0.1-0.2) via oscine_transport helps grooves.
Use slots as song sections: A groove, B variation/breakdown, C build, D drop. oscine_slots copy then mutate the copy. Switching slots while playing queues to the next loop boundary — switch live for the user.
Sound design: start from a preset (oscine_set_params preset:"Acid Bass"), then nudge params. oscine_preview auditions a pitch or drum hit without editing patterns.
Mixing: oscine_set_mix for level/pan/mute/solo and delay/reverb sends; oscine_set_master for the shared FX character.
Everything structural is undoable (oscine_project action:undo), so edit boldly.
Sharing the result: oscine_share action:"link" returns a URL with the whole song packed into it (no upload), good for handing the user something to open or post. oscine_export_wav bounces the active slot to a downloaded WAV (set loops for length, slot to pick a section).

Read the full file on GitHub · 53 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago Changed · +8 lines · +9 tokens per session 8f9b6d27da63
2mo ago First seen · 45 lines · 84 tokens per session scan B 0421fe887aad

Subscribe to this mod's changes

composing-with-oscine is a skill published in the GitHub repository chazmaniandinkle/oscine (0 stars, last pushed 22d ago), licensed MIT. It adds 93 tokens to every session and 1,918 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it B with 1 finding (subtle steering). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Creative and media

composing-with-oscine next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
composing-with-oscinechazmaniandinkle/oscine	Skill	0	22d ago	MIT	B	93	Claude Code
imagegenopenai/codex	Skill	134k	today	Apache-2.0	A	113	Codex
local-ai-agentsmicrosoft/ai-agents-for-beginners	Skill	79k	yesterday	MIT	A	200	Claude Code, Codex
playwright-climicrosoft/playwright	Skill	100k	yesterday	Apache-2.0	A	19	Claude Code
browser-automationopenclaw/openclaw	Skill	394k	today	MIT	A	36	Claude Code
systematic-debuggingobra/superpowers	Skill	314k	4d ago	MIT	A	21	Claude Code
next-cache-components-adoptionvercel/next.js	Skill	143k	today	MIT	A	95	Claude Code

composing-with-oscine