There is one scale that can take plenty of pedal without sounding in any way offensive, the whole-tone scale. Because all six notes of the whole-tone scale are the same distance apart, there is no leading note or tonic, thus no feeling of a stable tonal centre. The only triads possible are augmented ones, which feel the same in their inversions. Try an experiment. Put the right pedal down and play a whole-tone scale; if you do this fast and light, you will invoke the magical spirit of Tinkerbell herself. This arrangement between the hands works well, crossing over from right hand to left up and then back down as you like.

Debussy’s Voiles, the second Prélude from Book I, moves between whole-tone and pentatonic harmonies. If the whole-tone scale itself is ambiguous, so is the title. Voiles translates as sails or veils; the piece might be about either, or both. Currently set for ABRSM Grade 8, it offers the player vast scope for creating variety in touch and tone, skilful layering of sounds and subtle pedalling. I’m going to look at one or two things in the blog post that I hope will help you as you discover what is possible, especially with regard to pedalling.
Pedalling is always problematic in Debussy’s music since he left so few markings, preferring to leave it to the performer. Voiles contains the only pedal mark in Book 1 of the Préludes – the long pedal at the end.

Why was Debussy so reticent about marking pedalling in the score when he notated all other details of performance so scrupulously and painstakingly? It is of course impossible to notate the depth of sustaining pedal depression and indispensable techniques such as flutter and fractional pedallings, since these will inevitably vary from one instrument to another – depending on the performance space and, not least, the ear and good taste of the player. But we do find many clues for pedalling in the notation, as I hope to explain.
The first myth to bust is that a staccato marking or a rest preclude the use of the pedal. In this bass ostinato, touch can show up through the pedal provided the pedal is not all the way down. Experiment with a fractional pedal here, just enough to envelop the B flat in a mist but without drowning it.

We have already seen from our little experiment and the composer’s pedal marking at the end that whole-tone scale patterns sound very effective within the pedal, so I suggest pedalling lightly through the whole-tone double notes at the start. Don’t be squeamish – it will immediately feel and sound better to you. Pedal half way down before you start, and change on each beat of the bar, probably making more pedal adjustments in the four semiquavers (16th notes) at the end of the second phrase.

Let’s look at some long pedals. A long pedal is required from bar 33 to the downbeat of bar 37 to sustain the bass B flat – again, this is no problem at all since everything is whole-tone. In case you are wondering about the sostenuto pedal, Debussy never mentions it. While he would almost certainly have known some pianos with this pedal, I almost never recommend it for Debussy’s music for two main reasons: firstly, it tends to create an antiseptically clean texture when something more veiled or misty actually sounds better; secondly, the sostenuto pedal is often badly regulated (and therefore unreliable) even on very good pianos (if it is there at all).
I would invite you to try another experiment: play from bar 15 all the way to bar 42 in one long pedal just to see what maximum resonance sounds like to you. It will almost certainly be too much, but it is a good starting point. After you have tried it this way once or twice, adjust as necessary – you might prefer to change in bars 17, 19, 21 and 23, for example, and certainly I would want to hear a thinning in the texture in bars 31 and 32. Bars 33 – 37 will need one pedal, and while some players might want to change every bar from bar 48 – 62, it is feasible to hold the pedal through. There are plenty of other places where long pedals are very effective, but remember the pedal does not have to down all the way to the floor. Try putting the pedal half way down and holding it there. If the resonance becomes too much, fluttering the pedal may often work better than a full change.
One small thing that makes the right hand ostinato from bar 33 much easier to manage – finger both the D and the E with the thumb; the tempo is slow enough to manage this without any difficulty, and it enables easier hand positions later in the passage.

For me, by far the most convenient way to play the section from bar 50 – 54 is to take three notes from the top line with the left hand, which can easily cross over. This means the whole-tone pentascales can be fingered very naturally from 5th to thumb (LH) and from thumb to 5th (RH).

At the very end, release the pedal at some point as you hold the final C-E major third so that we hear these two notes alone as they disappear into the ether. As for the left pedal, it is so dependent on the piano you are playing and the sound you are after. But do remember it is there to be used, effective when you want muted colours and a veiled effect.
For an in-depth exploration of pedal techniques, please see my comprehensive series of articles and videos, The Art of Pedalling on the Online Academy.
I hope my video on advanced pedalling techniques for Pianist Magazine will also be of interest.