Scale-step

In Schenkerian theory, a scale-step (German: Stufe) is a triad (based on one of the diatonic scale degrees) that is perceived as an organizing force for a passage of music (in accordance with the principle of composing-out).

[1]A scale-step triad is designated by an uppercase Roman numeral representing the scale degree of the root, much as in traditional "harmonic analysis" (see chord progression).

However, unlike traditional harmonic analyses, Schenker's theory is not concerned with the mere labelling of such chords, but rather with discerning hierarchical relationships among tones.

The scale-step asserts its higher or more general character by comprising or summarizing the individual phenomena and embodying their intrinsic unity in one single triad.

Indeed, it follows from Schenker's concepts that, at the highest level, a tonal composition possesses only one scale step, since the entirety of the work may be understood as an elaboration of its tonic triad (i.e. scale-step I).