‘Middle C’ on Guitar
A commonly overlooked fact among guitarists is that Middle C on the guitar is not the same as Middle C on the piano.
Sometimes instruments have ranges that are very high or very low. Using standard notation would require a ridiculous amount of ledger lines. For this reason many instruments are tuned to different pitches other than concert pitch.
The guitar is an ‘octave’ instrument. So when you play middle C on guitar (3rd Fret of the A string) you are in fact playing a C note that is one full octave higher than the piano middle C. So the next time you attempt to play a piano piece on guitar remember to transpose everything up an octave.

Hi.
thanks for the great lesson
Thank you for the online guitar lessons especially on the middle c. There are also articles and resources which I have read on this learning how to play guitar and made me realize how guitar playing is