Today's article concludes the series of piano 101 in regards to the functionality of each of the three pedals on both the grand and upright pianos.
There are various types of middle pedals on an upright piano.
Sometimes, in few most expensive upright pianos, the middle pedal functions as a sostuneto pedal, working as its counterpart in the grand pianos.
Then in some upright pianos, the middle pedal functions as bass sustaining pedal, lifting up only the bass dampers to sustain the tones in the bass area.
Most of the time, the middle pedal in an upright piano serves as a 'practice' pedal. When this pedal is pushed down, it operates on a rod that contains a curtain of thick, soft felt, and causes the curtain to be positioned between the hammers and the strings. As a result, the energy transmitted from the hammers to the strings is mostly absorbed by the felt, causing the tone to be 'muffled'. Usually what you hear is a tone with a much 'quieter' volume. Thus the word 'practice' for this pedal, for this pedal provide you the chance to practice your piano at a quieter volume. In some pianos, the practice pedal could be pushed down and latched into a notch in the toe rail, causing the felt to be fixed at the position between the hammers and the strings throughout the practice period.