Exactly what the heck does the "middle pedal" do?greenspun.com : LUSENET : To Hear Ourselves As Others Hear Us : One Thread
Last week while I was teaching piano, one of my little students asked me to describe the purpose of the "middle pedal" on the piano. My upright piano does not have a middle pedal, but I thought to myself, gee, I don't even know what the middle pedal is called!... some piano teacher that makes me! Anyway, I promised her I would find the information, so I was delighted to see your website. Could you please provide me with the name and a description of the middle pedal?! Yours- Bailey McIntyre
-- Bailey McIntyre (email@example.com), September 27, 2000
Middle Pedal: 'Sostenuto pedal' (on grand pianos) 'Practice pedal' (on uprights)
on grand pianos, the middle pedal holds up the dampers of which ever key is being pressed at the time the middle pedal is depressed. thus you can 'hold' a few notes down (sustained - hence sostenuto - like having 3 hands to play the piano) while all the other keys and dampers act as normal. very useful for something like liszt's consolation no 3 in Db where you need to hold down the low Db in the left hand and still change the Right pedal with the harmony changes.
on uprights, most middle pedals pull down a thick sheet of felt that dampens the entire hammer action so the sound is on the whole, much quieter. suitable for practicing late at night, in crowded apartments etc.
-- Christian Gante (firstname.lastname@example.org), January 23, 2003.
On many uprights, the middle pedal does absolutely nothing at all. On others, it sustains only low notes. On some, it moves the hammers closer to the strings so they strike with less force and produce a softer sound (usually the function of the left-most pedal). Some uprights have a piece of felt that is inserted between the hammers and the strings when the middle pedal is pressed (the "practice pedal," as the previous poster described it).
On most good grand pianos, and some of the better uprights, the middle pedal is the sostenuto pedal that the previous poster also described, which sustains only the notes that are currently being played (selective sustain).
-- http://www.dilvie.com/ (email@example.com), January 26, 2004.