2.11 Pedals (Pedal Points, Pedal Tones)

In the next-to-the-last measure of Bach's Prelude in C from Book One of The Well Tempered Clavier, the bass note C, sustained for all four beats, does not belong to the G7 harmony of the right hand. This non-harmonic tone, most concisely called a "pedal," is unusual in that it usually appears in the bass. It is approached and left by the same note. In fact see the bass note C in every measure of the excerpt.

The C under the IV chord in the first measure of the last line is also considered a pedal because it forms a dissonant perfect fourth with the F's above it. In a strict sense this C is not nonharmonic; it does in fact belong to the accompanying F chord, but it is included here as a nonharmonic tone because it creates a dissonance which must be resolved. The resolution of both these pedal tones arrives with the E in the final tonic chord in the last measure. The C, as a pedal, never moves.
In general a pedal, or "pedal point" or "pedal tone," is a note that stays stationary while harmonies in other voices change. It is a nonharmonic pedal tone whenever it does not belong to a simultaneously sounding harmony.

Exception: If the bass of a second inversion chord is approached and left by the same pitch and if an upper voice resolves the dissonant fourth to a third, then this bass note is also called a pedal. This despite the fact that it is a member of the chord.

In four voices
on page 1.2
the primordial tonic was analyzed as having been expanded by two lower neighbors, but this expansion could just have easily been analyzed as a dominant triad in the upper three voices over a tonic pedal.
In the video to the left, there is the same ambiguity as on the top of page 1.2--Are two lower neighbors expanding an E minor triad or is a tonic pedal accompanying the dominant triad, B major, in the upper voices? In general the answers to questions like these depend on the context in a particular piece, the ear of the individual listener, and as we shall see in Chapter 3, the level of analysis.
Pedals can be shown more clearly in 4 voices with the insertion of a ii° chord before the dominant (The use of ii before the dominant will be covered in Chapter 4). In the video to the right, the tonic E pedal is not a member of the ii° and V chords. The resolution occurs not with the movement of the nonharmonic tone, but with the progression to a tonic triad in the upper three voices.
Listen to more pedals on the nonharmonic tones Contextual Listening page.

Comments? Click here.