This article was originally published on the Chamberlain Pianos Knowledgebase.
The first pianos evolved into what we know today as grand pianos, with the upright piano developed in the early 19th century as an affordable and compact instrument. The first upright was produced in Philadelphia, USA in 1800 by an Englishman named John Isaac Hawkins. Reportedly inspired by the clavicytherium - an instrument with harpsichord strings stretched over a vertical frame - his invention quickly became popular, with models including ornate novelty instruments such as the Giraffe Piano.
So, although both have black and white keys positioned at roughly the same height, two or three pedals, and usually some sort of fallboard and music rest combination, in many ways grands and uprights are distant cousins in terms of appearance.
Beyond pure aesthetics though, what are the key differences between these two types of acoustic pianos?
The action
A combination of design and physics dictates that a grand piano is a more capable and expressive instrument than an upright. While horizontal on a grand piano, the frame and soundboard of an upright piano are positioned vertically. The hammers in an upright are pushed forward to strike the strings, with springs to return them to their rest position once the note has been played. This mechanism enables a reasonably quick repetition, of up to 7 times per second. However, as the hammers in a grand piano are forced upwards to strike the horizontal strings and return downwards under the combined power of gravity and their own weight, repetition is much faster and more accurate, with a possible repetition speed of up to 14 times per second. Additionally, because upright pianos are designed for compactness, they typically have shorter key-sticks than a grand piano. Piano keys are much like a see-saw, they rest on a balance rail in the middle which acts as a fulcrum, and the further away from this point you depress the keys, the easier it becomes and ultimately the more control you have.
What about the pedals?
The pedals on most upright and grand pianos have slightly different functions too.
Left pedal
The left pedal on an upright piano is known as the half-blow pedal, often referred to as the soft pedal. Rather than making the piano sound discernibly quieter, it moves the hammers closer to the strings so that they hit them with less velocity. This allows the player to produce a sound which is a little quieter and softer.
On a grand piano the left pedal is known as the una corda (one string) or shift pedal, and moves the whole piano action including the keyboard slightly to the right. The result is that the hammer strikes fewer strings per note, making the sound quieter and changing its timbre.
Right pedal
This is known as the damper or sustain pedal and does the same job on both upright and grand pianos. When the pedal is depressed the dampers lift off each string simultaneously, allowing the notes to sustain.
Third (centre) pedal
The centre pedal on a grand piano is called a ‘sostenuto’. This pedal raises only the dampers of any notes depressed before the pedal is activated, thus enabling selective sustain. It can be very useful for keeping bass notes sustained when playing complex music, and is considered essential for many famous tunes written in the romantic era and beyond. For instance, Debussy’s ‘Clair de lune’, or Rachmaninoff’s ‘Prelude in C# minor’.
Most upright pianos have a third pedal known as the celeste or muffler pedal, which moves a thin piece of felt between the hammers and the strings in order to soften and quieten the sound. This is intended for practice purposes, rather than being a performance feature like the half-blow pedal. This pedal might otherwise activate a Silent System, so that the pianist can ‘switch off’ the acoustic part of the piano and simply put on some headphones or listen to the piano through some speakers. On larger Yamaha uprights including U3, YUS3/5, SE132 and SU7 models the centre pedal acts as a ‘sostenuto’, with a lever operated celeste mechanism.
Size really does matter!
Physics dictates that the quality of sound produced is largely influenced by the length of the string, and the smallest grand pianos have very similar speaking string length to the largest upright pianos. A longer string produces larger vibrations which not only make the sound louder, but also richer. The vibrations from the strings are then transmitted through the bridges and into the soundboard, which in turn acts like a loudspeaker to amplify the sound. Therefore, the longer the string and the larger the soundboard, the better the quality of tone produced.
This is why, when choosing a piano, the smaller models in a manufacturer’s range are described as beginner to intermediate level models, with the larger uprights and grands described as suitable for more advanced or professional musicians, who might require the subtle differences in touch and tone afforded by an instrument with a larger frame.
Refined materials
Larger instruments also tend to be materially better than smaller models, constructed from more refined components such as more mature spruce for the soundboard with fewer knots and a tighter, straighter grain, along with hammers made from selected hardwoods such as mahogany and double-felted hammers.
Naturally, the quality of tone wood also has an impact on the quality of tone produced. Larger pianos tend to have soundboards produced from spruce which is more mature, and specially selected for a tight grain and few imperfections to ensure the quality of sound isn’t compromised. Smaller upright pianos usually have less mature spruce soundboards, while entry level models such as the Yamaha b1 have laminated or engineered soundboards. The differences in the quality of tone produced by a better quality and more expensive soundboard are more discernible the larger the piano, so using cheaper cuts also enables the manufacturers to keep the price of the instrument at an affordable level. This is why, when choosing a piano, the smaller models in a manufacturer’s range are described as beginner to intermediate level models, with the larger uprights and grands described as suitable for more advanced or professional musicians, who might require the subtle differences in touch and tone afforded by an instrument with a larger frame.
So, when researching a piano purchase, it's always worth bearing these factors in mind - they might also help to explain why you prefer playing one type or another! Ultimately, it's always worth a thorough play test before you buy, but knowing some of the science behind the magic of these wonderful instruments is certainly valuable in making an informed decision.