Editing Pipe organ (section)

====Enclosure and expression pedals====
{{Main|Expression pedal}}
[[File:Salemer Münster Orgel Spieltisch und Pedal.jpg|thumb|The console of the organ in [[Salem Abbey|Salem Minster]] in [[Salem, Bodensee|Salem]], Germany.{{efn|Organ built by Wilhelm Schwarz, 1901}} The expression pedal is visible directly above the pedalboard.]]

''Enclosure'' refers to a system that allows for the [[Dynamics (music)|control of volume]] without requiring the addition or subtraction of stops. In a two-manual organ with Great and Swell divisions, the Swell will be enclosed. In larger organs, parts or all of the Choir and Solo divisions may also be enclosed.<ref name="swell">Wicks "Swell division", "Swell shades".</ref> The pipes of an enclosed division are placed in a chamber generally called the ''swell box''. At least one side of the box is constructed from horizontal or vertical palettes known as ''swell shades'', which operate in a similar way to [[Window blind|Venetian blinds]]; their position can be adjusted from the console. When the swell shades are open, more sound is heard than when they are closed.<ref name="swell"/>  Sometimes the shades are exposed, but they are often concealed behind a row of facade-pipes or a grill.

The most common method of controlling the louvers is the [[Expression pedal#Balanced swell pedal|balanced swell pedal]]. This device is usually placed above the centre of the pedalboard and is configured to rotate away from the organist from a near-vertical position (in which the shades are closed) to a near-horizontal position (in which the shades are open).<ref>Wicks "Expression pedals".</ref> An organ may also have a similar-looking [[crescendo pedal]], found alongside any expression pedals. Pressing the crescendo pedal forward cumulatively activates the stops of the organ, starting with the softest and ending with the loudest; pressing it backward reverses this process.<ref>Wicks "Crescendo pedal".</ref>