As your Wilmington DE Piano Tuner, I am often asked for the definition of standard pitch, and for an explanation as to why it is important. Here is a short explanation. Standard pitch is an arbitrary, agreed-upon pitch that allows instruments to play together. Without it, a symphony orchestra could not exist, for example, because the instruments must be tuned together so that they can be played together. Instruments are designed to play best at a specific pitch, and they do not play as well at other pitches. If we all agree as to what that pitch should be, then instrument makers can all work to produce instruments that work and sound best at that pitch.
Presently, the agreed-upon standard pitch is A-440. That means that the A above middle C on a piano should be tuned to 440 Hertz or 440 cycles per second. When you hear an orchestra tuning before a concert, they are all making sure their instruments are tuned together at A-440. Standard pitch has not always been 440. It has gradually been increasing for a couple hundred years, and it appears that it will continue to climb. Many orchestras are already playing at A-442, and the trend seems to be continuing. A concert piano tuner is frequently called upon to tune pianos to 442 to match an orchestra.
This all relates to piano tuning, because pianos are constantly changing pitch. If you leave a flute in a case for two years, and then pull it out to play, it will still be the same pitch as when you put it away. A piano, however, is a stringed instrument. Stringed instruments are constantly changing pitch. You may have noticed a violinist tuning between pieces in a concert. Stringed instruments are relatively fragile so that they will be resonant. The instruments flex with changes of temperature and humidity, and the strings go out of tune due to the stresses of playing them. A piano needs to be tuned regularly, or it drops in pitch. Typically a year is the longest interval to let a piano go without tuning, and all piano makers recommend tuning at least twice a year.
As your Wilmington De piano tuning expert, I am always available to answer your questions about pianos and piano tuning.