DemoPitch Tracker draws your voice or instrument as a live line on a piano roll. Sing, hum or play and your pitch scrolls across lanes labelled with every note, green within 10 cents of a note, yellow within 25 and red beyond, while the header shows the note, its frequency and how many cents off you are. Tap any lane to hear that note and make it your target; a drone can hold it while you sing. The roll follows your voice or shows a fixed bass, baritone, tenor, alto, soprano or wide range over the last 5, 10 or 20 seconds, and a score shows how much of the last 10 seconds you spent on pitch. Pause to study a phrase. Audio never leaves your device. Works on phones and desktops. Built with React, TypeScript and the Web Audio API.