Note Spectrogram
Semantic type: NoteSpectrogram · Category: analyzer
Passes audio through while exposing pitch confidence and unrounded estimated cent offsets across the 88-key piano range.
Use the opt-in decoded telemetry callback or subscription API to observe this effect. See Compatibility.
Contract
- Seeded: no
- Catalog sample rates: not declared; this does not mean unsupported
- Assets: none
- Catalog-declared latency: zero
- Telemetry: decoded semantic observations are available
| Semantic name | Python constructor keyword | Type / count | Default | Unit | Range or values |
|---|---|---|---|---|---|
minimumMidi |
minimum_midi |
integer / 1 | 28 |
Not declared in catalog | 21 … 108 |
maximumMidi |
maximum_midi |
integer / 1 | 91 |
Not declared in catalog | 21 … 108 |
timbreEnabled |
timbre_enabled |
boolean / 1 | false |
Not declared in catalog | Not declared in catalog |
EffeTune app documentation
The following section is reproduced from the English EffeTune app documentation. Its parameter names and values describe the app UI and can differ from semantic API parameters through transforms or value maps. The generated contract above is authoritative.
Note Spectrogram
Shows estimated fundamental pitches (F0s) from A0 to C8 in a scrolling piano roll without changing the audio. Use it to follow chord tones, vocal and melodic lines, bass lines, and overlapping notes across octaves, with optional instrument color-coding and highlighting.
Listening Guide
- Chords & Melodies: Chords appear as simultaneous bright rows; melodies and bass lines trace paths across note rows.
- Follow Vocals or Bass: Choose Instrument (3), or keep Note Colors and select Vocal or Bass in Highlight. Use Instrument (9) for finer instrument grouping.
- Estimate Accuracy: Pitch and instrument estimates are a visual listening aid rather than exact transcription. Overlapping sounds, percussion, or noise can produce ambiguous estimates, and drums are not classified. Instrument estimates use earlier notes as clues, so they are less reliable just after enabling them or moving the playback position; once ready, an estimate is not revised.
Instrument Groups
Instrument (3) groups pitches into Vocal, Bass, and Other (all groups below except Vocal and Bass).
Instrument (9) separates pitches into nine groups:
- Vocal: Recorded human singing, including solo voices and choirs.
- Bass: Acoustic, electric, and synth bass.
- Guitar: Acoustic, clean electric, and distorted guitars.
- Piano: Acoustic and electric pianos, harpsichord, and clavinet.
- Strings: Solo and ensemble strings, pizzicato, harp, and synth strings.
- Wind: Brass and woodwinds, including saxophones and flutes.
- Synth: Synth leads and pads.
- Organ: Organs, accordion, and harmonica.
- Other: Pitched percussion (celesta, vibraphone), synthesized choir/voice patches, synth effects, orchestral hits, ethnic instruments, and sound effects.
Parameters
- Color - Selects display colors without changing pitch detection (switching recolors existing history):
- Normal (default): Theme graph trace color.
- Note Colors: Distinct color per pitch class, repeated across octaves.
- Instrument (3): Colors for Vocal, Bass, and Other.
- Instrument (9): Colors for the nine instrument groups above.
- Highlight - Emphasizes a specific group (Vocal, Bass, Other (3), Guitar, Piano, Strings, Wind, Synth, Organ, or Other (9)) by shifting notes toward neutral gray the less likely they are to belong to that group, while preserving volume thickness. None (default) disables highlighting.
- Onset and instrument analysis use additional CPU. To minimize CPU usage, turn off Onsets, choose Normal or Note Colors, and set Highlight to None.
- Pitch Resolution - Selects vertical pitch detail without clearing history:
- 1/12 Octave (default): One row per semitone.
- High: Places pitches at their estimated cent positions to show vibrato and pitch bends.
- Layout - Horizontal (default, keyboard at bottom, history scrolls up) or Vertical (keyboard at right, history scrolls left).
- Volume - Encodes relative volume in bar thickness and keyboard-edge semicircle meters (on by default). When off, bar thickness is fixed.
- Onsets - Marks estimated note attacks with triangles (▼ in Horizontal, ▶ in Vertical; off by default). The center of each triangle’s base marks the attack time and pitch, so repeated attacks of a sustained pitch get separate marks. Turning it off does not stop instrument analysis while an Instrument Color or Highlight needs it.
- Time Span (1 to 10 s; default 2 s) - Duration of visible history on the piano roll.
- Lowest Note / Highest Note - Sets the analyzed and displayed pitch range (defaults: E1 to G6).
Visualization Guide
- Pitch Updates: New sound appears immediately and is refined about 40, 80, and 160 ms later using subsequent audio context, without adding display latency or affecting Sync Visuals to Audio.
- Grid & Keyboard: Lines at each C mark octave boundaries, E–F guides remain visible in all modes, and black-key rows use a darker background. Piano keys light up with current pitch confidence.
- Color Strength: Color strength always shows pitch confidence. When the input is too quiet for analysis, the piano roll stays dark.
- Instrument Colors & Highlight: Instrument colors blend the group colors by their estimated probabilities. Colors appear at the corresponding positions in the history once the instrument estimate is ready; notes awaiting classification appear in neutral gray. The legend lists the shown groups, followed by Highlight: and the selected group while highlighting is active. Hover over any group in the legend to highlight it temporarily.
- Volume Bars: With Volume on, bar thickness spans a 24 dB relative range, and a soft semicircle at the keyboard edge rises immediately with the current volume and falls at 20 dB/s.