level, Schicht. One of Schenker's most important concepts,
that the events of a tonal composition are ordered in a hierarchic
manner. The most important structural events occur at the background,
and form the fundamental structure.
Events of more local importance occur at higher structural levels,
the middleground and foreground,
and the ornamental and motivic detail occurs at the surface. Schenker
contends that, in general, all structural levels follow basic principles
of harmony and counterpoint. The progressions of the higher levels
are means of prolonging, or composing
out, the fewer but more important events of the deeper levels.
The example, from Variation 13, shows the middleground and
foreground levels. The foreground is more detailed, but by no means includes
every note of the surface of the music.