Why key detection gets the wrong key
A detector estimates a tonal label from the signal it receives. The input, the section, ambiguous harmony and the algorithm can all produce a result that disagrees with the music.
In this guide: SESSION™ Key. Apple silicon · macOS 14.4+ · Up to 3 Macs. Price and requirements.
Published by Capiscana, Inc., maker of SESSION™ products. About these comparisons.
On this page 8 sections
Check what entered the analyzer
A soloed drum bus, a quiet bass, another app playing, or microphone bleed can change the evidence. Confirm the intended input before arguing with the result.
Check the section
A short introduction, a borrowed chord or a modulation can change the local pitch evidence. Analyze a representative phrase and compare later sections.
Check the label convention
Relative major/minor, enharmonic spellings and modal music can produce apparently different labels. Determine whether the disagreement is spelling, tonal center, mode or an actual error.
Check with an instrument
Play the candidate tonic and relevant chord tones against the phrase. A confident display is still an estimate. Keep a correction when the listening evidence supports it.
Using SESSION™ Key
Read system audio, use the microphone, or drop an audio or MIDI file on the menu bar. Live analysis follows the passage playing; a file gives the analyzer a different span of material.
The outline marks a locked reading; green and amber communicate confidence separately. A locked reading can still be uncertain. Listen, check the musical context, and use the half-time or double-time control when the pulse needs it.
Put the result to work
Key and tempo in Pro Tools · Use Key with Ableton Live · Check a reading you do not believe · Compare analysis tools
Sources and scope
Product documentation reviewed October 17, 2026. These are comparisons of published capabilities, not independent performance tests. Prices and availability can change.
The musical explanations are editorial guidance; the product source supports the descriptions of Key. Check a disputed tonal label against the actual music.