(Ger. Schicht).
In Schenkerian analysis (see Analysis, §II, 4–6), one of a set of polyphonic representations of a piece or movement in which only some of the piece's harmonic and contrapuntal content is given. Layers are hierarchical; each subsumes and elaborates upon the content of the preceeding one until the final layer – represented by the score of the piece itself – is arrived at. (For examples of layer analyses, see Analysis, figs.16–17 and 21–2.)
The conceptual starting-point of a piece is its ‘background’ layer (Ger. Hintergrund); this is represented by the fundamental structure, or Ursatz, comprising a linear descent to the first note of the tonic triad (Urlinie) supported by the harmonic progression from the tonic to the dominant and back to the tonic (this is called the bass Arpeggiation). The layer whose representation most resembes the score of the piece itself, lacking only some detail, is called the ‘foreground’ (Ger. Vordergrund); this is usually the only layer before the score itself that shows the piece's rhythmic design and thus corresponds bar-for-bar with the piece. Between the background and the foreground lies the ‘middleground’ (Ger. Mittelgrund), made up of one or more layers. Schenker somtimes numbered these erste Schicht (‘first [middleground] layer’), zweite Schicht etc., the number of middleground layers being dependent upon the complexity of the piece and the amount of analytical detail he wished to show.
The analytical process is a reductive one; that is, it begins with the surface of a piece and proceeds to the foreground, the middleground layers and ultimately the Ursatz. But since analysis was, for Schenker, essentially the reverse of composition, he presented and discussed the layers in reverse order of their derivation, beginning with the simple Ursatz and ending with remarks on the content of the piece itself. In explaining the content of a subsequent layer, it would then be necessary to illustrate with musical notation (and, usually, to describe also in words) the various methods of Prolongation used to achieve increasing harmonic and contrapuntal complexity. The number of prolongations increases as one approaches the foreground; for this reason the musical representation of the foreground layer and the accompanying verbal commentary (if present) are the longest. Most of Schenker's analyses end with some remarks on the piece itself, the layer beyond the foreground; Schenker called this the Ausführung (literally ‘elaboration’, but more accurately rendered as ‘realization’).
For very short pieces it is possible to align all the analytical layers vertically, so that the methods of prolongation needed to get from one to the next may be studied conveniently. For pieces of moderate length, however, it is more practical for the foreground layer to be presented as a separate graph.
WILLIAM DRABKIN