Les sons et les parfums tournent dans l'air du soir (Préludes, Book 1, No. 4)

Background

This is the fourth prelude in Claude Debussy's first book of Préludes, composed in 1909–10 and published in 1910. Its long title, "Sounds and perfumes swirl in the evening air", is a line from Charles Baudelaire's poem "Harmonie du soir" ("Evening harmony") in Les Fleurs du mal. Debussy knew the poem well: more than twenty years earlier he had set it as a song, one of his Cinq poèmes de Baudelaire.

The poem describes a summer evening in which sounds, scents and memories blur into one another, turning like a slow, dizzy waltz. Debussy's marking at the start borrows the next line of the poem, asking for the "harmony and movement" of a valse mélancolique et langoureux vertige, a melancholy waltz and languid dizziness. As with all the Préludes, the title is printed at the end of the piece, so the player meets the music before the words.

How to practise it

This prelude is less about fast fingers than about listening. The harmony changes colour constantly, often by moving just one or two notes, and your job is to make each change audible.

The opening shows the idea in miniature. A rich A major chord is spread across both hands:

One beat later, everything slides to a new and much stranger chord:

Play these two chords back and forth slowly, listening to the colour change. Do the same with every new chord you meet: practise the pair, then the phrase.

Four further things to work on:

• The time signature keeps changing between five, three and four beats in a bar. Count every bar out loud until the changes feel natural.
• A low A often sounds beneath the chords as a held bass note. Where a chord is struck together with it, as in bars 3, 4, 9, 11 and 26, Debussy marks the chord m.d. (main droite, right hand): the right hand reaches down for the chord while the left hand plays the A. Elsewhere the left hand plays both, one after the other, and the pedal holds the first while the hand moves.
• From about bar 17 the right hand repeats a small pattern on C sharp and D sharp in two octaves while the chords move beneath it. Keep the pattern quiet and even.
• Around bars 41 to 45 the climax sweeps right across the keyboard. At the start of bars 41, 43 and 44 the right hand plays the first group of sixteenths in octaves while the left hand strikes the deep octave below. Practise these bars in small groups, hands separately, before joining them.

The last bars are very quiet, with soft, distant calls in the middle of the keyboard above the lowest A on the piano.

A plan: hands separately at 40 beats a minute, then together at 40, 52 and the full 63. Use plenty of pedal, but change it with every new harmony, listening for blur. Keep the overall level soft, so the few louder moments glow rather than shout.

Another of Debussy's preludes is in this library as an excerpt: La fille aux cheveux de lin.