Tweaking the timbre, the una-corda pedal. Rêverie, Debussy.

Published by Paul on

As you may have deduced from my blogs up to now, I’m a lover of pianists who make the piano “sing” and are keen on working with the sound, the timbre.

Much of that is done by controlling the touch in a very refined manner as to evoke beautiful, interesting sounds from the instrument. But apart from the touch the piano itself has tools which we can use in our quest for the ultimate sound: the pedals. Both the sustain and the una-corda pedal, the right and left pedal.

Note: when talking about the left or una-corda pedal, I mean the left pedal on a grand piano, not on an upright. They differ in their mechanism, see PS below.

In the earlier “ Blending the sound” blog I talked about the right or sustain pedal.
Today I would like to introduce the left or una-corda pedal, sometimes also referred to as soft-pedal. Soft-pedal is a term which does not reflect the actual effect of the pedal: when depressing the left pedal the keyboard moves slightly to the side. In most grand piano’s to the right, in some brands to left.
This movement results in not all strings being hit (una-corda means one string). So the sound gets softer but also changes in timbre, color.

Beside that: by moving, the grooves in the hammerhead do not align anymore with the strings, so the string gets hit by the softer felt. Resulting in a more mellow sound. Some pianist use the una-corda pedal also when nót playing soft, solely for the change in timbre.

Taking all this into account on could say the una-corda pedal can be used as a kind of equalizer, changing the timbre of the tone. Like a sound engineer when doing the master mix after the music has been recorded. The pianist does it in real time, while playing.

After my Bechstein had it’s major revision last year I was very focussed on how to influence the tone with the new feel of the action. Zooming in on how to produce the desired sound the una-corda pedal also had to be taken into account. One of the things I experimented with was to use different levels of depressing the pedal, keep it there for some time, then slowly move up (or down). As to disperse the effect over longer a line, longer a time.

To my regret, my pedal got stuck, didn’t move fluently after being held for some time in an in-between position. So I turned to Frans, my piano technician, once again. He came up with a stronger spring, with two touch points with the keyboard instead of one.  A Steinway spring, so now there’s a  “fremdkörper” living in my Bechstein 😉 .

The piece I tried this on, Debussy’s Reverie, is a very evocative, dreamy, yet not sentimental piece. Quite popular with the advanced pianostudent.
Debussy didn’t like it that much, he wrote it because he was out of money.  “I wrote it in a hurry years ago, purely for material considerations”.

I’m not sure my recording equipment is sophisticated enough to record the subtleties of change in una-corda pedal I try in this rendition of Reverie. If not, I only have one advise: give it a try yourself!

The left pedal on an upright piano has a totally different mechanism: it pushes the hammerheads closer to the strings. The idea being, I guess, to play soft more easily. But as a result of pushing the hammerheads up to the strings the contact of the action with the key is lost, there is some “air” before the key touches the action. Which feels like a badly regulated action. In other words: to me, the left pedal on an upright is quite useless.

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August Bekkers
2 months ago

I recognise the discussion 😉 But, i must admit that i have difficulty in recognising when exactly the pedal is used. Separate it from playing more soft all-together by controlling the touch of the fingers. Do I understand correctly that there are piano’s build fully according to the una-corda principle? What is the advantage of that?

August Bekkers
2 months ago
Reply to  Paul

Thanks – clear response. I have an up-right piano. When with a grand piano (Austerlitz !?) I will give it some extra attention …

2 months ago

Interesting subject and nicely played Paul !