Nota Scale

Nota Scale is a MIDI effect that constrains the notes reaching an instrument to a musical scale. Anything you play (or any MIDI clip) is remapped to the nearest in-scale note, so wrong notes become right ones — useful for playing in a key you don’t know, taming generative or chance-based sources, or locking a part to a mode.

Overview

Nota Scale sits before an instrument in a track’s device chain and rewrites note pitches as they pass through:

MIDI in ─▶ range gate ─▶ snap to scale (root · mask · fold) ─▶ transpose ─▶ MIDI out

Notes inside the scale pass straight through. Out-of-scale notes are folded to an in-scale note. Notes outside the range limiter are left untouched, so you can scale a melody register while letting held bass or pedal notes through.

Interface

The card (mockup 3b) is a live strip over a note map and a side rail.

• Live strip — ROOT stepper (◂ / ▸ to move the tonic), the scale-type chips Major · Minor · Dorian · Phryg · Penta · Custom, and the FOLD selector Nearest · Down · Up.
• Note map — the twelve pitch classes as a 6×2 grid. In-scale notes glow amber; the root is outlined in green and labelled root; out-of-scale notes show a teal arrow (e.g. → D) to where they will fold. Click a cell to add or remove that note — doing so switches the scale to Custom. The header counts how many notes are remapped (5 of 12 remapped).
• Right rail — LAST IN → OUT shows the most recent remapped note and its shift in semitones; RANGE sets the low–high note window (drag each value); FOLLOW KEY makes the root track what you play; Learn / Clear build or wipe a Custom scale.

Parameters

Parameter	Range	What it does
Root	C–B	The tonic the scale is built on.
Scale	preset · Custom	The scale mask. Card presets: Major, Minor, Dorian, Phryg, Penta. Custom is the freely editable 12-note mask.
Transpose	-24…+24 st	Shifts the note after it snaps to the scale.
Fold	Nearest · Down · Up	Which direction an out-of-scale note moves to reach the scale.
Range Low / Range High	0–127	Only notes within this window are snapped; notes outside pass through unchanged.
Follow Key	on / off	The root follows the dominant pitch class of your recent playing.
Learn	action	Builds a Custom scale from the notes you just played.
Clear	action	Empties the Custom scale so you can draw one from scratch.

Tips & recipes

• Play safely in a key: pick a Root and a preset, set Fold to Nearest, and every note lands in the scale.
• Bass through, melody snapped: raise Range Low above your bass register so low notes pass untouched while the upper range is constrained.
• Capture a scale you like: play a phrase, hit Learn, and Nota Scale rebuilds the Custom mask from those notes.

See also

• MIDI effects run before the instrument on a track, in the order you add them.
• Interface tour — where the device chain lives.