Auto-Chart — Advanced Options

The Advanced disclosure in the Auto-Chart modal exposes everything you can tune about a generation run.

Tracks to chart

By default OCTAVE produces all five instruments. Uncheck any to skip its stage entirely:

• Drums — kick / snare / cymbals / toms from the drums stem
• Guitar — pitched guitar from the other stem
• Bass — pitched bass from the bass stem
• Keys — pitched keys from the other stem (off by default — usually noisy)
• Vocals — lead melody from the vocals stem
• Harmonies (HARM2 / HARM3) — additional harmony lines (off by default)

Skipping a track shaves real time off the run — drums-only is the fastest configuration.

Manual BPM & tempo map

By default the tempo is detected automatically. If detection misbehaves you can provide your own:

• Manual BPM — a constant tempo (one number)
• Tempo map editor — a list of (time, BPM) events for songs with tempo changes

When a manual tempo map is provided, OCTAVE retimes the auto-detected events to that grid using mido — so notes still land on bars/beats correctly.

Use this when you already know the song's tempo (e.g. you have a click track from the original session).

Offline mode

Skips any network calls — no model downloads, no yt-dlp. Requires:

• The bundled Python runtime to already be present (run Auto-Chart once online first).
• All required model weights cached locally.

Useful for charters working offline or in CI.

Output structure

A successful run produces a folder named after the song:

My Song - Some Artist/
├── notes.mid          # Full chart
├── song.ini           # Title, artist, charter, length, etc.
├── drums.ogg          # Drums stem
├── bass.ogg           # Bass stem
├── vocals.ogg         # Vocals stem
└── song.ogg           # Everything else (the "other" stem)

Drop the folder into your YARG / Clone Hero songs library and it's playable immediately.

Performance tips

• Use a GPU — the bundled runtime auto-detects CUDA on Windows / Linux and Metal on macOS.
• Pre-split stems — if you already have stems, point Auto-Chart at the folder. Skipping Demucs cuts ~40% of runtime.
• Skip Keys & Pro Guitar — these are the noisiest output and rarely worth keeping for typical pop / rock material.

Where logs go

Every Auto-Chart run writes a log file you can attach to bug reports:

• Windows: %APPDATA%/octave/logs/strum-<timestamp>.log
• macOS: ~/Library/Logs/octave/strum-<timestamp>.log
• Linux: ~/.config/octave/logs/strum-<timestamp>.log