OnKey

OnKey is a free open-source singing trainer that listens to music playing on a Mac, learns the melody, and displays a pitch guide.

OnKey is a free and open-source singing trainer designed for Apple Silicon Macs running macOS 14.2 or later. It listens to music playing through Spotify, Apple Music, or YouTube, learns the singer's melody during the first play, and displays a scrolling pitch guide. While singing, the interface highlights accurate pitches in green and off-pitch notes in red. Afterward, users receive a score, note accuracy details, and a playback recording alongside the original song. The application requires no account, features no analytics, and operates entirely locally without saving the source music. Unlike traditional singing applications that rely on built-in catalogues or hand-made charts, OnKey uses core machine learning and per-app audio capture to work directly with existing music libraries.

OnKey at a glance

Best for: Student
Runs on: macOS
Pricing: Free and open source
Released: October 2026
Category: AI audio tool
Website: singonkey.app

Key features

Listens to system audio to learn melodies
Displays a scrolling pitch guide
Generates singing accuracy scores
Records microphone input for playback
Recognises songs using Shazam
Fetches synced lyrics from LRCLIB
Operates locally without user accounts

Use it for

Practicing vocal pitch accuracy using favorite songs
Reviewing recorded singing sessions alongside original tracks
Learning song lyrics and timing automatically

Alternatives to OnKey

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Handy — It runs completely offline and keeps your voice data private on your computer.
DOT Audio Recorder — Records internal Mac audio with no driver installation and detects key, BPM, and chords.
FlexChords — Achieves 92 percent chord accuracy on unseen songs.
Moises — Isolate up to 27 stem types with Hi-Fi models and practice music efficiently.
Mi Speaks 2.0 — Generates twenty-eight human-sounding neural voices completely offline on the device.
Voiskey — Dictation that cleans up fillers and matches the intended tone
ZenMic — It offers full line-by-line script editing and custom voice controls.
Book2Speech — It converts DRM-free books into audiobooks with hundreds of natural AI voices and read-along highlighting.
Buzz Transcriber — Transcribes and translates audio offline directly on personal computers.

All OnKey alternatives