What is backing-tracks CLAUDE.md?

Project instructions for a Go command-line program that plays full-band guitar backing tracks defined in YAML files. YAML is a human-readable text format for structured settings such as tempo, chords and drum patterns.

It helps with the track parser and with features involving chords, bass, drums, timing and the live terminal display.

It gives an agent the context needed to change the right part of the program without breaking how track files are parsed, checked or played.

How ako/backing-tracks configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to ako/backing-tracks. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/ako/backing-tracks/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/ako/backing-tracks

Made for: Claude Code.

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/instructions/ako/backing-tracks/claude-md/github.svg)](https://agentmods.dev/instructions/ako/backing-tracks/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/ako/backing-tracks/claude-md"><img src="https://agentmods.dev/badge/instructions/ako/backing-tracks/claude-md/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/instructions/ako/backing-tracks/claude-md"><img src="https://agentmods.dev/badge/instructions/ako/backing-tracks/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 3,366 This file is loaded in full into every session.

When invoked 3,366 The same file — it is already loaded in full.

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	$0.03366	$0.03366
Opus 5.5	$0.01346	$0.01346
Sonnet 5.5	$0.00673	$0.00673
Haiku 4.5	$0.00337	$0.00337

Measured 2mo ago against content hash 3cdbc6e2286d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

backing-tracks CLAUDE.md 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 2mo 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo apt install fluidsynth fluid-soundfont-gm

CLAUDE.md · 410 lines

How it starts

The opening of the file, as written. The whole thing — 410 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Claude Project Context: Backing Tracks

Project Overview

This is a terminal-based backing track player written in Go that uses YAML-based DSL (Domain-Specific Language) called BTML (Backing Track Markup Language) to define complete backing tracks for guitar practice.

Current Version: v0.7

Purpose: Enable guitarists to create and play full-band backing tracks (chords, bass, drums) from simple YAML files, with real-time visual display showing current chord and beat.

Architecture

┌─────────────────────────────────────────────────────────┐
│ BTML File (.yaml)                                       │
│ - Track metadata (tempo, key, time signature)          │
│ - Chord progression (pattern string)                   │
│ - Bass configuration (style, swing)                    │
│ - Drums configuration (presets or Euclidean rhythms)   │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│ Parser (parser/parser.go)                               │
│ - Parses YAML into Go structs                          │
│ - Validates and sets defaults                          │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│ Display (display/terminal.go)                           │
│ - Shows track info, chord grid, bass/drum info         │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│ MIDI Generation (midi/)                                 │
│ ├─ generator.go: Main MIDI file creation               │
│ ├─ bass.go: Bass pattern generation                    │
│ └─ drums.go: Drum pattern generation (w/ Euclidean)   │
│                                                         │
│ Output: 3-track MIDI file                              │
│ - Track 0: Tempo metadata                              │
│ - Track 1: Chords (channel 0, piano)                   │
│ - Track 2: Bass (channel 1, fingered bass)             │
│ - Track 3: Drums (channel 9, GM drum map)              │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│ Live Display (display/live.go)                          │
│ - Real-time chord and beat visualization               │
│ - Updates 10x/second via goroutine                     │
│ - Visual metronome, progress bar                       │
└─────────────────────────────────────────────────────────┘
                          ↓
┌─────────────────────────────────────────────────────────┐
│ Player (player/fluidsynth.go)                           │
│ - Executes FluidSynth via exec.Command                 │
│ - Manages live display lifecycle                       │
│ - Synthesizes MIDI to audio using SoundFont            │
└─────────────────────────────────────────────────────────┘

Read the full file on GitHub · 410 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.

2mo ago First seen · 410 lines · 3,366 tokens per session scan B 3cdbc6e2286d

Subscribe to this mod's changes

backing-tracks CLAUDE.md is an instructions file published in the GitHub repository ako/backing-tracks (20 stars, last pushed 10mo ago), licensed MIT. It adds 3,366 tokens to every session, about $0.0135 per session on Opus 5.5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Creative and media

backing-tracks CLAUDE.md next to 6 instructions from other repositories
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backing-tracks: Instructions file for Claude Code