Bouzouki (4 strings) & (3 strings) Sound

Heya all
Have a question/issue, when I am starting creating a
whole new Music Sheet through the creator wizard, although I choose a specific instrument, Bouzouki
( 4 strings) or 3 strings, even if I add this instrument at the default list where piano
is already there, all I hear while playing the sheet is the piano. Even as stand alone
instrument or even if its been added in the instruments list. I keep hearing
the piano sound. No clue of Bouzouki sound. Not even close to its sound. Is there something i have to do and i dont so far?
Hoping for a respone, thank you.