(MUSIC) Can someone explain to me how to write nice sounding harmonies in music? I dunno how at all.

Answer" probably want to move your harmony too, to a chord to which 'D' is a strong relation.  write down the melody notes.

i got an a+! !

including the octave, the answer would 8 notes in a major scale with one note being played twice. ex) c major scale includes: c, d, e, f, g, a, b, c

notice that c is played twice

however, if you were to ask me how many different notes are in a major scale- the answer would be 7.