Introduction

The prelude begins with a 31-bar introduction. Several details suggest the use of a musical language typical of southern Spain:

• The semitone with which it begins is characteristic of the Phrygian mode, a mode commonly used in this style.
• The rhythmic pattern similar to that of the hemiola: two notes (F - Gb) within a ternary rhythm.
• The title The interrupted serenade.
• The indication of quasi guitarra.

The first motif - which we will call the guitar motif - uses the first two notes of the Phrygian mode and will be developed harmonically and melodically:

Measures 9 to 11

• The C flat of measures 6 and 8 is a note of the Locrian mode, presented as descending and ascending scales.
• In measure 9, we see the natural C is part of the Phrygian mode. It is the first variant of the guitar motif.

Measures 11 to 18

The first ten measures are repeated slightly varied in bars 11 to 18. The C-flat from the Locrian mode reappears:

Measures 19 to 31

• In measures 19 to 23, Debussy insists on the chords of F dominant (I degree of the Phrygian mode) and B flat minor (IV degree) using various extensions.
• The use of the major chord over the first degree of the Phrygian mode is typical of southern Spain's music, despite the clash between the major third of the chord and the minor third of the mode.
• The semitone motif continues its development in the inner voice in measures 19 to 23.
• This dissonant semitone is found in the augmented ninth on the F chord and the augmented eleventh on the B flat.
• From bar 25, insist again on the guitar motif with the semitone F - G flat doubled to the fifth.
• The introduction ends in measures 31.

First Chant

• From measure 32, a melody that recalls southern Spain's cante jondo is presented over the guitar motif.
• The melody uses the notes E-F, the first notes of the mode of my Phrygian.
• The natural E of the melody creates a dissonance with the bass F.
• The semitone appears between the notes F-Gb, C-Db, and E-F.

Paavali Jumppanen, piano
Isabella Stewart Gardner Museum
Creative Commons Attribution-NonCommercial-NoDerivs 4.0

Measures 41 to 47

• The chords from measures 19 interrupt the chant in measure 41.

Measures 47 to 54

• The key signature disappears on measures 47 to 50.
• An E dominant chord with minor ninth and thirteenth alternates with other chords.
• At bar 51, the key signature and the Locrian mode at bar 5 return.

Second Chant

• Chant reappears - this time more developed - in measures 65 to 83.
• The guitar motif accompanies it, but this time with more chromaticism.
• The melody moves over the F Phrygian mode notes using the A natural from the harmony.
• A dominant E flat harmony is established with ninth, augmented eleventh, and thirteenth extensions at measure 74.
• E flat dominant resolves to the A-flat dominant in bar 80.
• A-flat takes us to D-flat major in measure 84.
• The Chant concludes the section insisting on the Phrygian with the natural.

Paavali Jumppanen, piano
Isabella Stewart Gardner Museum
Creative Commons Attribution-NonCommercial-NoDerivs 4.0

Measures 91 to 100

• From D flat, we surprisingly move to D major.
• The measure changes to 2/4, and the tempo calms down.
• They interrupt the introduction's chords at bar 96, but we return in 98 in D major in 2/4.
• The chords from the introduction return at bar 101 to prepare the last appearance of the chant.

Paavali Jumppanen, piano
Isabella Stewart Gardner Museum
Creative Commons Attribution-NonCommercial-NoDerivs 4.0

Third Chant

• The melody develops over a B flat pedal tone.
• The pedal changes to an E-flat dominant chord at measure 124.
• At measure 128, the ninth becomes minor.
• At measure 132 the chord becomes minor.
• In bars 135 and 136, we return to the chords of the introduction.

Paavali Jumppanen, piano
Isabella Stewart Gardner Museum
Creative Commons Attribution-NonCommercial-NoDerivs 4.0

Final measures

• The introduction's chords are repeated (138-139), followed by the descending Locrian mode and the guitar motif (140-144).
• The prelude ends on B flat minor.

Complete Prelude

Paavali Jumppanen, piano
Isabella Stewart Gardner Museum
Creative Commons Attribution-NonCommercial-NoDerivs 4.0

Paavali Jumppanen, piano
Isabella Stewart Gardner Museum
Creative Commons Attribution-NonCommercial-NoDerivs 4.0