Chopin, Raindrop prelude, op.28, no.15
The very first premise related to concept pedal is that its pitch is sustained. When the identity of a pedal is primarily formed by its absolute of relative pitch, changing of the pitch implies the termination of the pedal. This is true of the harmonic pedals. Some other types of pedals are not primarily defined by their exact or relative pitch. In case the timbre or the rhythm of the pedal are the defining factors, change of its pitch might be less relevant. This situation is recognized in Chopin’s prelude op.28, no.15.
The pedal establishes itself in the first bars. Its pitch is the fifth in the key. Its rhythmic pattern is not constant, but it consists almost constantly out of unaccented notes. In comparison with the rhythm of the melody, we see that the pedal tone rarely sound at the moment the important melodic notes sound. It seems that the pedal tones are complementary with the other rhythmic events in the piece.
In its ‘exposition phase’, in the opening of the piece, the pedal is consonant, provides constant rhythmic pulsation (by sounding all the eighth notes that accompaniment does not), and the steady pitch. The first four bars get the consequent phrase and the pedal still shows the same properties. The listener understands this is an instance of Rhythmic pedal in the upper (accompanying) voices model.
In the first eight bars, everything is simple and transparent: the form, the harmony, and the melody. The middle section of the first part of the prelude (starting in m.9) starts on the dominant, and the pedal still remains what it was. We have entered the middle section knowing what kind of pedal this is. And that is crucial because this section is, compared to the first one, not simple; the attention of the listener is automatically focusing on the elements that change and the processes that should be understood.
The form gets blurred by the implications of the melody and the harmonic organization. The phrase begins on the dominant, but even more important, the melodic line inclines towards the Gb in m.10 (harmonic reasons) which puts weight on m.10. The result is that m.10 sounds as a beginning. Similar happens four bars later. The boundaries of the phrases in this section are blurred and the listener needs some mental capacity to understand the phrase. The harmonic rhythm is faster, and there are more bass notes to move the harmonic listening (see the blue arrows in the image). The key becomes instable, first due to the tonicizing of the subdominant, then tonicizing the minor V (or modulating to Ab minor), then with the series of ascending fifths, the key reaches Bb minor. After this point in m.15, everything stabilizes again. And so it stays until the opening theme returns in m.20.
The listener was focused on the dynamic events, attentively following the harmonic and the melodic plane. The pedal tone was out of the focus but it felt as if it did sound all the time: we have heard the expected rhythmic activity in the pedal-register. In m.20 the pedal is again clean and clear. But is it the same tone?
The answer is NO. We have modulated and the new pedal is F, again the fifth of the key. The pedal is modulated together with the rest of the music. Its pitch has changed but its identity hasn’t. It is the same pedal from m.1, only with different pitch. The pedal-model that we have recognized, has interacted with the perception of the unchanged pulsation, perception of the fast harmonic changes and the process of understanding the structure. A possible result is that the listener could have the feeling that the ‘raindrops’ are constantly falling: the raindrops, the same thing.
After realizing the small ternary form of the A part, B part is announced by the rhythmic pulsation of the same pedal. It is continued throughout the B part. In this section, the pedal has taken the full responsibility for the pulsation, as it is the only accompanying voice for some time. The key is changed into its minor variant, and the texture is a kind of inverted. In the first part, it was the low voice (although the bass occasionally sounded lower). In the second part, it is the top voice (the melody will occasionally sound higher (e.g., in m.36)).
In m.35 the pedal tone becomes doubled in the octave; this prepares the variation of the first phrase in m.36. In m.40 the doubled pedal moves a third up, to be again the fifth of the current chord. After four bars, it returns to the original position, to host the recapitulation of the first theme from B.
Although its pitch is not constantly Ab/G#, the rhythmic pedal of the prelude op.28, no.15 is recognizable throughout the piece. Its identity is the same, it is just the raindrops. It rains the whole day.