Until I read about it recently on Wikipedia, I didn't realize that the guitar is a transposing instrument. That it is notated one octave above, and therefore is played one octave below, concert pitch. In order to cut down on the number of ledger lines needed.
So unless I'm turning things around, to play a middle C on guitar at the same pitch as a piano, the guitar must play an octave higher than noted in the sheet music for guitar.
As a beginning student I would like to take this opportunity to again say "YIKES!" Well at least unlike an A, Bb, of Eb clarinet, the guitar is only "off" an even octave.