Notes · No. 1
July 29, 2026
On this piano the una corda lives on the shift key. On nearly every grand piano in the world, the leftmost pedal answers to the same name. It is not a brand, not an acronym, not a piece of engineering jargon. It is two ordinary Italian words, and they mean something disarmingly literal: one string.
Una is simply the Italian word for one — in its feminine form, because corda is a feminine noun. Corda is string, and it is an old word with a long pedigree: it descends from the Latin chorda, which the Romans borrowed from the Greek khordē — a string made of gut, which is what the strings of ancient lyres actually were. The same ancestor gave English its cord, and lent its spelling to chord. When you press the una corda pedal, you are — etymologically speaking — asking for one length of gut, on an instrument strung with steel.
The word rarely travels alone. Scores that ask for the pedal also have to release it, and the release instruction is part of the same family: tre corde — three strings — or tutte le corde, all of them. Between the two extremes sits the rarer due corde, two strings. The whole vocabulary of this pedal is nothing more than counting.
Because a piano note is a choir, not a soloist. Look inside a modern grand and you find that most keys sound not one string but three identical strings tuned in unison; the tenor makes do with two heavier wound strings, and only the deepest bass notes speak through a single massive copper-wound one. Multiple strings per note mean more power and a longer, richer sustain — and they also offer the oldest trick in the book for a softer, stranger sound: strike fewer of them.
The trick is as old as the instrument. Bartolomeo Cristofori, who invented the piano around 1700, strung his instruments with two strings per note and already provided a way to slide the keyboard and its whole mechanism sideways, so that each hammer reached only one string of its pair. One string: una corda. The name was not poetry; it was a description.
And that is still the mechanism, three centuries later. Press the left pedal of a grand and the entire action glides quietly to the right by a few millimetres — sit at one and you can watch the whole keyboard shift under your hands. Nothing about the hammers' speed changes; what changes is what they land on.
Here the arithmetic breaks, charmingly. On a modern grand with three strings per note, the shift is shallow: the hammers land on two strings of the three. Today's una corda is, strictly speaking, a due corde. The name has outlived its own count — we keep saying “one string” the way we keep “dialling” phones, as the ghost of an older machine inside the words.
On the pianos of Beethoven's time the arithmetic was still honest. The shift worked by degrees: three strings, two, and at full depth genuinely one. Beethoven trusted the device enough to write the counts into his scores like organ registrations. The slow movement of the Hammerklavier sonata, op. 106, breathes between una corda and tutte le corde; and in op. 101 — the sonata whose directions he wrote in German — he asks for mit einer Saite, “with one string,” and later nach und nach mehrere Saiten: “little by little, more strings.” A crescendo made of string-count — an effect no modern piano can literally give him anymore.
The surprise, the first time you truly listen, is that the una corda is not mainly a volume pedal. Two strings out of three are barely quieter than three. What changes is the color, and it changes for two reasons the name doesn't mention:
Which is why composers ask for una corda at every dynamic, not just the quiet ones — you can play forte under the pedal and get something muffled and enormous, like weather behind glass. The una corda doesn't turn the volume down. It changes who is singing.
The left pedal of an upright piano is a different creature wearing the same shoe. An upright's action cannot slide sideways, so its pedal does the only thing available: it moves all the hammers closer to the strings. A shorter runway means less speed at impact, and less speed means a softer blow — the half-blow pedal. Same strings, same felt, same color; just quieter, and often with a slightly shallower touch.
So an upright's “soft pedal” genuinely is a soft pedal — while a grand's una corda is something better: a different instrument, rented for a phrase. The two share a position and a shoe-print, and almost nothing else. The name, strictly, belongs only to the grand.
On Piano 1024 the una corda sits on shift, beside the sustain on space, and like the sustain it comes in two modes — hold, momentary like the real pedal, and latch, toggled with a tap. There is no action to slide here: the sound is synthesized, so the model reaches for what the listener actually hears. Under the una corda, each note is struck more gently than your dynamics alone would strike it, and its high partials are reined in — the same softening and veiling the shifted hammer buys on a grand, written in equations instead of felt. (The synthesis itself has its own page.)
Try the word. Set Una corda to Latch in the console, tap shift, and play a phrase — then release it and play the same phrase at the same dynamics. What changes is not how loud the piano is. It is how far away the light seems.