Multiple Strings
All but the lowest notes of a piano have multiple strings tuned to the same frequency. This allows the piano to have a loud attack with a fast decay but a long sustain in the ADSR system.
The three strings create a coupled oscillator with three normal modes (with two polarizations each). Since the strings are only weakly coupled, the normal modes have imperceptibly different frequencies. But they transfer their vibrational energy to the sounding board at significantly different rates.
The normal mode in which the three strings oscillate together is most efficient at transferring energy since all three strings pull in the same direction at the same time. It sounds loud, but decays quickly. This normal mode is responsible for the rapid staccato "Attack" part of the note.
In the other two normal modes the strings do not all pull together, e.g., one will pull up while the other two pull down. There is slow transfer of energy to the sounding board, generating a soft but near-constant "Sustain".
Read more about this topic: Piano Acoustics
Famous quotes containing the words multiple and/or strings:
“Combining paid employment with marriage and motherhood creates safeguards for emotional well-being. Nothing is certain in life, but generally the chances of happiness are greater if one has multiple areas of interest and involvement. To juggle is to diminish the risk of depression, anxiety, and unhappiness.”
—Faye J. Crosby (20th century)
“it was older sure than this year’s cutting,
Or even last year’s or the year’s before.
The wood was gray and the bark warping off it
And the pile somewhat sunken. Clematis
Had wound strings round and round it like a bundle.”
—Robert Frost (1874–1963)