Upright piano action: upright piano internal operation.
Felt: cloth surrounding the hammer.
Hammer: piece that hits the string to make it vibrate.
Hammer rail: hammer support when it is not operated.
Catcher: piece that catches the hammer tail when it falls.
Back check: piece that catches the hammer tail when it falls.
Key: part of the keyboard that is pressed to produce a note.
Wippen: piece to which the strings are attached and that transmits the sound to the soundboard.
Jack: piece that sends the hammer head towards the string.
Hammer butt: part of the hammer that is pushed by the jack.
Spring rail: support for the damper when it is not operated.
Damper: piece that prevents the string from vibrating.
String: part of the piano that produces the sound by vibration when hit.
When a piano key is depressed slowly, it rocks on the center rail and goes up in back. The key raises the sticker and wippen. The wippen pushes the jack, which pushes the hammer butt. The hammer butt pivots on its flange and moves the hammer toward the string. When the key is half way down, the spoon engages with the damper lever, lifting the damper off the strings. When the hammer is almost to the strings, the jack heel bumps into the regulating button, and as the wippen keeps going up, the jack pivots and slips out from under the hammer butt. The hammer continues under its own inertia to the string, instantly rebounding.
At this point the strings start vibrating, the vibrations are carried to the bridge which transmits the vibration to the soundboard (the large, thin wood piece you can see in the back of the piano) which amplifies the sound (like a big speaker).
The catcher is caught by the back check and held in this position as long as the key is depressed.
When the key is released, the wippen drops, the back check releases the catcher, the briddle tape gives a little tug on the hammer butt, and with the help of the butt spring, the hammer returns to the hammer rail. The damper spring returns the damper to the strings, and the jack spring returns the jack under the butt, ready for the next repetition. This entire sequence occurs in a fraction of a second, allowing the pianist to repeat notes rapidly.
Tim Hendy demonstrates, in the video below, how the modern upright piano action works. Using a full scale working model, he demonstrates the actions of the key, hammer, damper, damper rest rail, balance hammer, check, lever and jack, concluding with concise recommendations for piano maintenance.
Greetings to Everyone and A Big Welcome to Infinity Music Studio! My name is Suzanne Brittania. I have been teaching piano and voice lessons for over 40 plus years. It is my hope that you will find all the following information, along with the music videos listed within my blog, to be very interesting, helpful and inspiring all throughout your own musical journey.
The videos listed below are of famous opera stars (that I performed with extensively all throughout my earlier musical career) especially during the 1950's and 60's.
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