IntervalKit

IntervalKit is a music practice site by aleshh. On Hacker News the author said it started as a vibe-coded guitar scale fingering generator and grew to cover chords, scales and instruments such as piano, cello and alto recorder.

Pick an instrument and a scale, and it shows where each note sits on the fretboard or keyboard, linking theory to your hands. Switching among several instruments in one tool is what sets it apart from single-instrument charts.

Who it's for:learners studying theory who want to map scales and chords onto a real instrument.

Before you start: it opens in a browser; we only confirmed the page loads and didn't use it. Accounts, pricing and phone use aren't stated. The related source repository, gtr-scales, has no license, and its README still points to the older site, so the two versions differ. The interface language isn't stated; the documentation is in English.

Based on the project page and the author's post on Hacker News. Not tested by AI Inspiration World.