What frequency is middle C on a piano?

Hello Gvs and thank you for your question.

According to the Penguin Dictionary of Music, the middle C, the note C
found at approximately the middle of the piano keyboard is commonly
tuned to 261.6 Hz. frequency.

Source:
The Penguin Dictionary of Music
http://www.xrefer.com/entry/355959

According to this piano key frequency chart
http://www.engr.smu.edu/ee/1301/doc/piano.doc
from the Southern Methodist University - School of Engineering, the
middle C of the piano has a frequency of 262.

When middle C is played on the piano, it produces a sound with a
frequency of 262 Hz.
The Indiana University High Energy Physics web pages
http://hep.physics.indiana.edu/~rickv/waves.html

Additional information that may interest you.

Theory of music with sound samples, where you may to the middle C and
compare it to the higher C.
Source:
Southern Methodist University Website
http://www2.smu.edu/totw/pitch.htm

Search Criteria:

frequency middle C +piano


I hope you find this helpful and if there is anything that I've
written that needs clarification, please ask before you rate this
answer.

Best Regards,
Bobbie7-ga

Very good anwsers and quick response