Editing Piano (section)

=== {{anchor|grand piano|concert grand piano|parlor grand piano|boudoir grand piano|baby grand piano}}Grand ===
{{redirect|Grand piano|other uses|Grand Piano (disambiguation)}}

[[File:Piano in Entrance Hall.jpg|thumb|[[Steinway & Sons]] grand piano in the [[White House]]]]
In a '''grand piano''', the frame and strings are horizontal, with the strings extending away from the keyboard. The action lies beneath the strings and uses gravity as its means of return to a state of rest. Grand pianos range in length from approximately {{cvt|1.5|–|3|m|ftin|sp=us}}. Some of the lengths have been given more-or-less customary names, which vary from time to time and place to place, but might include:

* Baby grand – around {{cvt|1.5|m|ftin|sp=us}}{{sfn|Fletcher|Rossing|1998|p=352}}
* Parlor grand or boudoir grand – {{cvt|1.7|–|2.2|m|ftin|sp=us}}
* Concert grand – between {{cvt|2.2|–|3|m|ftin|sp=us}}{{sfn|Fletcher|Rossing|1998|p=352}}

All else being equal, longer pianos with longer strings have larger, richer sound and lower [[inharmonicity]] of the strings. Inharmonicity is the degree to which the [[frequency|frequencies]] of [[overtone]]s (known as partials or [[harmonic]]s) sound [[sharp (music)|sharp]] relative to whole multiples of the fundamental frequency. This results from the piano's considerable string stiffness; as a struck string decays, its harmonics vibrate from a point very slightly from its termination toward the center (or more flexible part) of the string. The inharmonicity may also result from imperfections within the string, such as rust on plain strings and dirt in the windings of bass strings.{{sfn|Richardson|1998|p=106}} The higher the partial, the further sharp it runs. Pianos with shorter and thicker string (i.e., small pianos with short string scales) have more inharmonicity. The greater the inharmonicity, the more the ear perceives it as harshness of tone.

The inharmonicity of piano strings requires that octaves be ''[[Pseudo-octave|stretched]],'' or tuned to a lower octave's corresponding sharp overtone rather than to a theoretically correct octave. If octaves are not stretched, single octaves sound in tune, but double—and notably triple—octaves are unacceptably narrow. Stretching a small piano's octaves to match its inherent inharmonicity level creates an imbalance among all the instrument's intervallic relationships. In a concert grand, however, the octave "stretch" retains harmonic balance, even when aligning treble notes to a harmonic produced from three octaves below. This lets close and widespread octaves sound pure, and produces virtually beatless [[perfect fifth]]s. This gives the concert grand a brilliant, singing and sustaining tone quality—one of the principal reasons that full-size grands are used in the concert hall. Smaller grands satisfy the space and cost needs of domestic use; as well, they are used in some small teaching studios and smaller performance venues.