Prolonging the Fundamental Structure (cont.)
Prolongations of the Fundamental Structure (Bass Prolongations)
The bass line in the foreground can be prolonged by all the same diminutions as the top line, although it tends to be somewhat simpler because of its supporting role.
In the first level middleground the prolongations of the bass line are very limited, only occuring between the initial I and V.
One common way in which the bass can generate longer spans of a piece of music is shown in the example below. The leap from I to V is turned into a rising arpeggiation - Schenker calls this a third-divider because it divides the fifth into two thirds.
The first example creates a first inversion tonic chord which does not give much scope for extended prolongation but in the second example the E becomes a scale step creating the opportunity for a section in E major. This is particularly common in the minor where III is the relative major.
The thirds either side of divider can be filled in with passing notes or the bass may consist of just scale step II or IV. Schenker lists the possible permutations in Figure 15 of Free Composition, the example below shows just one of the many listed here.
Back to Guide
On to How to do a Schenkerian Analysis