If art is subjective how can anyone really critique it? some artists choose to reject all formal skills and techniques and adopt a more emotional approach?

answer; opinion;

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.