Music Scale Finder — listens to whatever's playing in a tab and figures out which musical scale/key the song is in.
Users
12
+3 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
1
0 in 30 days
Store rank
#179K
#149K among extensions
Version
0.1 (Beta)
updated 10 Jul 2026
Users
monthly, 3 months
Latest, 15 Oct 2026:12 usersMove the mouse over the chart for any month
Ratings count
monthly, 3 months
Latest, 15 Oct 2026:1 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About 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.