About
Hexatonic is a practice tool for six-note scales, built at Nathaniel School of Music by Jason Zac.
Ṣāḍava (षाडव) is the Carnatic term for a six-note raga. Its siblings are already named by the tradition — audava (five) and sampūrṇa (seven) — which is why the name carries the roadmap.
The theory is computed, not asserted
Everything this app states about a scale — its spelling in any key, the chords available inside it, the interval content of a drill, the bar on which a pattern resolves — comes from an engine that is unit-tested against a reference implementation. Nothing is typed in by hand and hoped for.
What it claims
That it is the only free, browser-based app built entirely around hexatonic practice. And that no other tool generates melodic patterns in Carnatic rhythmic groupings and reports which bar they resolve on.
What it does not claim
It is not the “world’s first hexatonic app”. An iOS app named Hexatonics has existed since January 2025, and mDecks’ Tessitura Pro has shipped bi-triadic hexatonic practice — with pattern generation, notation and odd meters — since 2017.
Two naming points, because both are commonly got wrong. The “gospel scale” is not the scale here — that name means 1 2 ♭3 3 5 6, the major blues scale. And the “Sunday scale” is Peter Martin’s term for something else again. The names used throughout this app are modal-intersection names, which follow Cecil Sharp’s folk-song classification and describe the ambiguity the removed note creates.
Credits
Piano is the Salamander Grand. Engraving is VexFlow. The Carnatic terminology was checked against the literature and carries an explicit list of things that could not be verified — where a source could not be confirmed, the app stays quiet rather than guessing.