Prolongation.

In Schenkerian analysis (see Analysis, §II, 4–6), the generation of the harmonic and contrapuntal substance of a piece by a linear elaboration of its fundamental structure (Ursatz). Methods of prolongation may be applied to the upper voice or the bass, or to one of the inner voices arising from early stages of elaboration; they may also link an inner voice to an outer one, or the two outer voices to each other.

An analysis of part of the main Allegro theme of the first movement of Haydn's Symphony no.104 in D, taken from Schenker's Der freie Satz (1935), will help to illustrate some of these methods. The Ursatz (ex.1a) is prolonged by an Interruption after the arrival of 2 over the dominant, which necessitates a return of the opening 3 over the tonic and the eventual completion of the motion 3–2–1 in the second half of the theme (see ex.1b). To reach the next stage (ex.1c; after Schenker, 1935, fig.95a/5), the first bass note, d, is brought into a higher octave (d') by an ascending Register transfer. This d' initiates a linear progression (see Zug (i)) through the interval of an octave which returns to the original d before proceeding to the dominant. The upper part imitates the octave with a linear progression of its own, beginning on d'' and proceeding in 10ths with the bass until it, too, regains its starting note, f'. This sixth-progression is preceded by an unfolding of the tonic chord, f'–a'–d'', called an ‘arpeggiation’ (see Arpeggiation (ii)). The arrival on the dominant in bar 8 is delayed by a 6/45/3 suspension, itself a type of prolongation.

Other methods of prolongation include Coupling, Initial ascent, Motion from an inner voice, Reaching over and Unfolding.

WILLIAM DRABKIN