OKay, i'm new with the sax and needed some guidance from my family on this site about mouthpieces, i was looking up on website about mouthpieces to purchases, they, have like model C , model E, model D, etc... does this give the sax a different tune? when i play the note G on my sax it comes out a different sound then the note on the piano, so if i'm reading music and i play C or G, and i tell the pianist to play in the key of C or G, we're on two different notes, does this has anything to do with the mouthpiece or the saxophone itself?