When should the sustain pedal be used in Debussy's Clair de Lune, given the fast tempo?

Question

In recordings of Clair de Lune, I can hear that the sustain pedal is used almost throughout the entire piece, including in the middle part, which is played at a rather fast tempo. Since the sustain pedal is not marked in the sheet music, I used the pedal whenever it sounded right as I learned the piece, which means that I kept it held it down for almost the entire duration of the middle part.

Recently, I tried playing the piece on a grand piano that is placed in a fairly small room, and the sound was different from the way it sounds on the digital keyboard that I normally practice on. Perhaps due to the small room and the grand piano's power, the notes seemed to reverberate a lot more and there was more discord/notes being drowned out through use of the pedal.

A normal practice when playing chords with the pedal is to reset the pedal during each new chord, but when there are just single notes played at a fast tempo, you can't really do this because the foot moves much more slowly than fingers. Is there a good way to deal with resetting the pedal during fast pieces, or is the answer just to keep the pedal held down and avoid playing fast pieces using the pedal in a small room?

Clarification: by the middle of the piece, I am referring to the section "Un poco mosso", bar 27, up to bar 51, "A Tempo I": https://musescore.com/classicman/clairdelune. Especially in bars 45 and 46, I can barely hear the melody in the left hand due to it being drowned out by everything else.

Answer 1

Some people believe that if something is Debussy it is impressionist and thus requires heavy pedal. That is not true. Debussy’s piano music tends to be very articulate and needs to be played transparently. Debussy himself experimented a lot with how to use the pedal, and with ways to use the pedal without affecting transparency too much.

In the score he actually writes in the beginning con sordina, with damper. I think this instruction intends to prevent people pressing the forte pedal continuously like it is usually done, but to use the dampers to prevent ringing and to get more transparency.

In this context I think it is quite revealing to hear Debussy’s own recording of this piece (the recording comes from a set of piano rolls that were recorded on a very sophisticated system of the time, recording both pedaling an dynamics (!!!) (less complicated systems required these to be added to the roll manually afterward), thus giving a very good reproduction of how Debussy actually played this).

I think this is quite revealing. It is fast (under 4 Minutes!), much less romanticized as we are used to, not dreamy, but like a song, very uneven and very transparent. In total this shows a very clear, connected structure and development we miss from the modern, slow, even and dreamy interpretations.

So point is: Use pedal, but do not just press it down. Experiment with how often you switch pedal and with how deep you press the pedal, until you get something you are satisfied with. And do not feel forced to give much pedal if it does not work in a place, as that is not what Debussy intended.