Beethoven has given us the following mystifying instructions at the beginning of the Moonlight Sonata: ”Si deve suonare tutto questo pezzo delicatissimamente e senza sordino” which in plain English means to put the damper pedal down for the entire movement. This, on the pianos in Beethoven’s day, would have achieved a hazy effect, which was the esthetic of the day. Carl Czerny, Beethoven’s student and the composer of all those etudes, called it “a nocturnal scene, in which a mournful ghostly voice sounds from the distance.”
If we pedal exactly as indicated on our modern piano, the sound, of course, will be muddy to the point of ugly. There are several ways around it but here is the most intriguing. In his book Keyboard Interpretation from the 14th to the 19th Century, Howard Ferguson suggests a way to achieve the desired effect if you have a sostenuto pedal: silently depress the lowest 8 notes on the keyboard, then catch them with the sostenuto pedal, and play and pedal as you normally would. The sympathetic vibrations will cause that haze. I tried it and it sounds marvellous! It does take a few bars for the vibrations to set in, but then we get that ghostly, mournful sound.
I’m not sure I would get a student to do this for an exam – one never knows what an examiner might say – but it is a lovely effect, and it would be a good way to teach about the overtone series and sympathetic vibrations. Most students don’t have a piano with a sostenuto pedal, so a more practical alternative would be to half-pedal here and there to capture some sustained sounds while keeping it clean enough.
Interestingly, as is the case with a number of other composers’ famous pieces, the Moonlight was very popular in Beethoven’s day and this annoyed him. He said to Czerny, “Surely I’ve written better things!”