zplane TONIC 2 is a key and scale detection plugin released on 21 October 2026. Insert it on any audio or MIDI track and it reads the key and scale in real time, showing up to three matches with a percentage probability for each. You can also drag an audio file onto it for offline analysis.
Version 2 reworks the detection algorithm for faster, steadier readings and adds writing tools. Chord mode maps compatible chords to a virtual keyboard and lets you drag them into the DAW as MIDI clips, while Fold Keys remaps the notes of the selected scale onto the white keys of a MIDI keyboard so you only play in-scale notes. MIDI in and out, note and chord auditioning, and a tuning display that reads deviation from A = 440 Hz in cents and hertz round it out. Formats are AAX, AU and VST3 on Windows 10/11 and macOS 13 or later, with no latency.
TONIC 2 lists at 39 euros with a 33% launch discount, and TONIC 1 owners upgrade for 10 euros. For DJ-focused library tagging and harmonic mixing, Mixed In Key is the better fit; for deep chord and progression building, Scaler 3 goes further. See the full TONIC 2 first look.