DJ analysis

Crateforge performs DJ-oriented audio analysis with a pure-Rust DSP. Without depending on external tools, it estimates BPM / Key (Camelot) / Energy / loudness and a similarity vector.

Screenshots to be added

What gets analyzed

Metric	Description
BPM	Detects tempo automatically. Lets you find tracks that are easy to mix.
Key (Camelot)	For harmonic mixing, shows the key in Camelot notation (e.g. `8A`).
Energy	Quantifies a track’s drive. Lets you design the flow of a set.
Loudness	The volume level. Used for rendering the real waveform and for normalization.
Similarity vector	An internal representation for pulling in tracks with a similar vibe.

Of the analysis results, Key / Energy can be shown as columns in the track table and are also shown in Now Playing.

Key notation and manual override

Notation — In Settings → “一般” (General) → “Key 表記” (Key notation), choose how keys are displayed: Camelot (8A) / Open Key (1m) / Classic (Am / F#m). Only the display changes; stored values, compatibility checks and search stay in Camelot. Search accepts any notation: key:8A, key:1m and key:Am all match the same keys.
Manual override — If the analyzed key is wrong, pick the correct one in the Key field of the track editor (Get Info / Ctrl + I). The override is stored separately from the analyzed value and survives re-analysis. Choose “解析値を使う” (use analyzed value) to clear it. Overridden keys are shown with a * in the track table.
When a track has an override, the override is used everywhere: display, search (key: / key:compat:), smart playlists, Similar, Set Lint and the file-tag (InitialKey) write-back.

When analysis runs

Analysis runs in the background only for “the tracks you use often.” It is triggered by either of the following.

When you play a track
When you run “Analyze” via right-click

Analyzed BPM / Key are also written to the actual file tags when you edit a track (BPM and InitialKey — see Library import for details).

Progress is shown in the toolbar. Rather than analyzing your entire library at once, it focuses on the tracks you actually use, so it works without waste.

Similarity-based curation (Similar Digging)

The Similar tab in the right rail suggests “next moves” based on analysis values.

Right-click a track and choose “Find similar” (or press Ctrl/Cmd + Shift + S) to show candidates that are Camelot-key compatible + close in tempo.
The base track can be the selected track or the playing track; unpin it and it follows whatever is playing.

Digging further (history)

Choosing “Set as base” on a candidate row makes that track the new base so you can keep digging.

Back / Forward and the breadcrumb move through the base-track history of the session. Clicking a breadcrumb jumps back to that point (Clear resets the history).

Why it is similar (reason chips)

Each candidate carries chips describing its relation to the base track.

Key — the candidate’s Camelot key (shown as 8A → 9A when it differs from the base)
BPM — the difference from the base (BPM +1.5 / BPM -2.0%, etc.)
Energy — the difference from the base (Energy +0.08, etc.)
Harmonic — the key is harmonically compatible
d= — the distance in the similarity vector space

Filters

Harmonic — Camelot-compatible keys only (independent of the BPM filter)
BPM tolerance — the allowed difference relative to the base
Energy close — only an Energy difference of 0.15 or less
Exclude tracks in the Crate / exclude the same artist / ★★★ and above only

These filters are saved and carried over to the next launch.

Row actions

Each row offers Preview / set as the dig base / play next / add to the Crate. Candidates can also be dragged and dropped into the Crate, and double-clicking previews them. When everything has been added, “Add all” is disabled (“All added”).

You can also filter by analysis values in search (AND-combined with text search and other field filters).

bpm:120-128
key:8A
key:compat:8A
energy:60-100
analyzed:no

A single bpm: value matches ±2 and prefers the analyzed value (falling back to the track’s BPM tag).
key:compat:8A narrows to every key that mixes harmonically with 8A (8A / 8B / 7A / 9A). The base key can be written in any notation (key:compat:1m / key:compat:Am). It uses the same logic as the Similar tab, so the two never disagree.
energy: accepts either 0–1 or 0–100.
analyzed:yes / analyzed:no separates analyzed from not-yet-analyzed tracks.

For the full syntax, including filters on artist, year, and rating, see search syntax.

Integration with Smart Playlists and AI curation

You can use BPM / Key / Energy in Smart Playlist rules.
The built-in API server also returns analysis results and similar tracks, so AI curation such as dj-curator can leverage analysis values as a bonus.