Key Changer
Detect Audio Keys & Transpose
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
Detect the key and tempo of songs from live listening or audio files, then transpose to a different key if needed. Transposing chord chart files is also supported.
Key Changer helps musicians make music fit their voice, instrument, and group. Find a song's key, transpose audio recordings, and transpose chord charts into the key you need.
AUDIO FILE TRANSPOSITION
• Import an audio recording and detect its musical key
• Choose a new key and transpose the recording
• Preview the transposed result before exporting
• Share your new version in M4A or WAV format
LIVE AUDIO DETECTION
• Use your iPhone microphone to listen to music playing nearby
• Capture a 12-second sample to estimate a song's key and tempo
• Helpful for rehearsals, live performances, and learning songs by ear
CHORD SCANNER
• Choose a current key and target key for a chord chart
• Point your camera at a chord sheet to see transposed chord labels as you scan
• Capture a snapshot, or import a PDF or image of a chord chart
• Review and share a transposed chart for practice, rehearsal, or performance
Key Changer is made for vocalists finding a comfortable range, worship leaders preparing charts for their teams, bands adapting songs for live performance, music students, and anyone learning by ear.
All audio analysis and chord recognition happen on your device. No account or subscription is required. Clear audio and easy-to-read chord charts provide the best results; automatic key and tempo results are helpful estimates, so trust your ears too.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
The developer, Joseph Ratterman, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Joseph Ratterman
- Size
- 6.4 MB
- Category
- Music
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Joe Cool Coder