The person who wrote the song in the form of notation and pass on to others to play it is called ..

Composer

Explanation:

Someone who records the notation for a physical piece for another person or group of people to play is called a composer.

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.