Scalefy

Scalefy listens to whatever's playing in a browser tab and tells you
which musical scale (key) the song is in — great for musicians who want
to jam along, transcribe, or just understand a song faster.

HOW IT WORKS
1. Play a song in any tab (YouTube, Spotify Web Player, SoundCloud, etc.)
2. Click the Scalefy icon and hit "Start Listening"
3. Pick that tab in Chrome's share picker
4. Scalefy listens for about a minute, then confirms its best guess —
the detected scale, its notes, and a confidence rating
5. Click "Check Next Song" anytime to analyze something new

WHY IT'S DIFFERENT
- No sign-up, no account, no downloading audio files
- Runs entirely on your device — audio is analyzed in memory and never
recorded, saved, or sent anywhere
- Uses an established music-theory approach (key-profile correlation)
rather than guessing from a black-box model

WHO IT'S FOR
Guitarists, pianists, producers, music students, or anyone who's ever
paused a song and thought "what key is this even in?"

LIMITATIONS (we'd rather be upfront)
Works best on tonal music with a clear key center — pop, rock, folk, and
most Western music. Less reliable on atonal music, songs that change key
partway through, or very noisy/percussive audio.