Piano Improvisation Helper
This small app looks up a song, analyses an available preview and shows the likely key with alternate guesses, giving a starting point for playing along.
Independent development. React, TypeScript, Web Audio and pitch-class analysis.
I made this around the moment of wanting to play along with a song, and the first version starts with a title and artist search before looking for an audio preview it can analyse, with the preview providing the audio material and the manual search keeping the initial interaction straightforward.
The detector decodes the preview in the browser and builds a pitch-class histogram across audio frames, then compares that distribution with major and minor key profiles to rank the possible keys.
The UI keeps alternate guesses visible and lets the analysis run for longer, though microphone-based song recognition is still a placeholder in this version and the implemented path starts with manual search.
The catalogue date follows the first preserved commit on 12 December 2025.
Outcome
A working search and preview-analysis interface with in-browser key detection and service tests. Results are estimates from the available clip, with alternate candidates shown.