3.4. Key Profiles and Key Guide

The contour and reference-SPL controls choose the active key profile. That choice belongs to the active Mix and is used consistently by Library, Mix, Gems, and Gem Finder.

ECMA-418 is the release default. None uses calibrated-flat evidence. ISO 226:2003 and ISO 226:2023 are phon-dependent profiles, so their result also depends on the selected reference SPL. Switching between these profiles is immediate because the scan already retained the required harmonic evidence.

Open Key Guide from a detected key to compare major/minor character or the six supported advanced modes across all twelve tonic roots. The guide can preview matching local Library tracks and add or replace a Mix track. It is an exploration surface, not a second analysis mode.