Put another way : for key signatures with sharps , the first sharp is placed on F line with subsequent sharps on C , G , D , A , E and B ; for key signatures with flats , the first flat is placed on B with subsequent flats on E , A , D , G , C and F . There are thus 15 conventional key signatures , with up to seven sharps or flats and including the empty signature of C major ( A minor ) .
There are fifteen possible key signatures : up to seven sharps , up to seven flats , or no sharps or flats .