One day last week, a couple of friends and I were doing a "garage band" type thing, and one of them say hes going to play rhythm while I play lead. He asked me if I knew B sharp scale(or something like that). He said to play this scale because he was capoed to the third fret. Also he said that capoing to the third makes it B sharp.
I don't really understand why putting a capo on the third fret makes it B sharp, and what kind of scale would go along with a rhythm guitar capoed to the third while I'm not using a capo at all?