OpenTune
Key Features
- Neural-vocoder pitch correction designed to preserve vocal formants during tuning and transposition
- RMVPE pitch extraction with PC-NSF HiFiGAN resynthesis through ONNX Runtime
- Graphical editing workflow with hand-drawing, note editing, anchor tools, and automatic tuning
- Automatic key detection plus scale correction for Chromatic, Major, Minor, Pentatonic, Dorian, Mixolydian, and Harmonic Minor modes
- Standalone application and VST3 plugin builds, with ARA2 extension support in compatible hosts
- GPU-accelerated inference using DirectML on Windows and CoreML on macOS
- Multilingual interface support for Chinese, English, Japanese, Russian, and Spanish
Description
OpenTune is an open-source vocal pitch correction tool that combines a standalone editor with a VST3 plugin workflow. Instead of basic DSP transposition, it uses RMVPE pitch extraction and a PC-NSF HiFiGAN neural vocoder through ONNX Runtime to regenerate corrected vocals while aiming to preserve the singer's formants.
The editor is built around graphical tuning rather than one-knob automatic correction. You can draw pitch curves, edit detected notes, use anchor tools, detect key automatically, correct to common scales, and work in ARA2-capable hosts when the host integration behaves correctly.
This is still beta software, so the production fit is different from a polished commercial vocal editor. The strongest use case is experimental manual vocal tuning for producers who want to try neural resynthesis, accept large installer sizes, and can work around unsigned macOS packages, uneven host support, shifting release assets, and interface/documentation rough edges while keeping original vocal takes backed up.
Frequently Asked Questions
Is OpenTune closer to Auto-Tune or Melodyne?
OpenTune has automatic tuning features, but its workflow is closer to graphical editors like Melodyne because it centers on detected notes, drawn pitch curves, anchors, and manual correction. It is best treated as an editor for recorded vocals rather than a simple real-time hard-tune insert.
Why is the installer so large?
OpenTune ships with neural pitch extraction and vocoder components rather than relying only on small traditional DSP routines. The current release assets and earlier BPB testing both point to unusually large downloads for this type of vocal tool.
Does the VST3 version work in every DAW?
No. The developer notes that ARA mode requires a host with ARA2 support, and BPB's test found the standalone macOS app worked while the VST3 did not appear in Studio One during that pass. Use the standalone version first if plugin scanning is unreliable.
Is OpenTune safe to use on macOS?
The official README says current macOS release packages use ad-hoc signing and are not Apple-notarized, so macOS may show security warnings on first launch. Follow the developer's installer instructions and keep original vocal recordings backed up before using beta software in a session.
