TONIC by Zplane is an AI-powered music theory plugin that identifies the key of any audio track in real time and suggests compatible scales and chords for creating melodies, basslines, and harmonies.
Purpose
TONIC is a music theory plugin designed to remove guesswork from key detection. It analyzes any audio recording—whether a loop, a song idea, or a full mix—and displays up to three likely keys with a confidence indicator. This helps producers, musicians, and beatmakers understand the tonal foundation of their material.
The plugin works directly in a DAW: insert it on an audio track, press play, and it processes the sound in real time. It supports mono and stereo sources. Use it to identify keys in remix projects, to match samples from a record collection, or to name the key of a live performance you recorded yourself.
Key Capabilities
One standout feature is the fold-out Keyboard View. Once a key is suggested, you can expand a piano-style display that shows the notes and chords belonging to that key, enabling you to experiment with compatible melodic and harmonic ideas. This turns key detection into a practical composition tool.
TONIC also includes reference tuning detection for recordings that deviate from the standard A440 pitch. This ensures accurate analysis of older or non-standard recordings. Additionally, an offline mode lets you analyze audio files before loading them into a sampler, saving time during sample preparation.
Workflow
To use TONIC, place it on any audio channel in your DAW and start playback. The plugin listens and updates its key suggestions in real time, displaying confidence levels so you can judge how reliable each result is. After selecting a key, open the keys panel to see the available scale notes and chords.
This workflow is especially useful for adding new parts to existing material: knowing the key and scale lets you compose basslines, melodies, or harmonies that fit. It also speeds up remixing, as you no longer have to manually test different notes or use external tools. The offline mode complements this by allowing key checks on files before they enter your project.
Practical Applications
For remix producers, TONIC helps identify the key of a vocal or instrumental track, making it easier to blend with other elements. For sample-based producers, it ensures that loops and one-shots from different sources are in the same key, reducing dissonance. It also aids in music education by showing the relationship between key, scale, and chords.
Musicians recording live performances can use TONIC to name the key of each take, which is valuable for cataloging and later arranging. In songwriting sessions, using the plugin can suggest harmonic directions you might not have considered. Its real-time analysis makes it a practical tool for both studio and creative experimentation.
Key features
- Detects key in any audio recording in real time
- Presents up to three suggested keys with confidence levels
- Fold-out keyboard view shows compatible notes and chords
- Supports mono and stereo audio sources
- Reference tuning detection for non-A440 recordings
- Offline mode for analyzing audio before loading into samplers
Best for
TONIC is best for beatmakers, remixers, and sample-based producers who need to quickly identify the key of audio tracks, find compatible chords and scales, and integrate theory-based decision-making into their DAW workflow. It is also useful for musicians documenting live recordings and educators teaching key relationships.