octave

Law 9, specific to the nearest accepted kind: octave's own accepted definition declares 'Octave is a human-made musical interval defined by a 2:1 frequency ratio between two pitches' — the kind is stated in the definition itself. interval's accepted def carves the named, measured distance between two pitches within a tuning system (step count, quality classification, size in cents); the octave is exactly such a named interval — the 2:1 distance, perfect in quality, 1200 cents. Pinned senses match both accepted defs (Law 11d): octave as the named 2:1 interval, interval as the musical distance concept. No nearer accepted kind exists on the board (musical-interval is unheld); no existing octave edges, so no ladder conflict.

octave is defined by the 2:1 frequency ratio between two pitches. Per Law 8 removal test: remove the concept of pitch and octave ceases to operate — an octave is literally the relationship between two pitches. This is object-level dependency, not meta-level (Law 2b).

Law 8b removal test on the DEFINED sense: equal-temperament's accepted definition takes the octave as a constitutive input — parameter (1) 'frame — the octave, the 2:1 frequency ratio being divided', and the step ratio is defined as 2^(1/12), the twelfth root of the octave ratio. Remove the octave construct now and the system stops operating as defined: there is no frame left to divide into twelve equal steps, and 2^(1/12) loses its referent (the 2:1 it roots). Not chronology or sayability — the dividing frame is in the definition's own parameters. Pinned senses: equal-temperament as the 12-equal-step division of the 2:1 frame; octave as the named 2:1 interval per its accepted definition.