Nicolas Poussin outlined the principles of classicism and described the essential ingredients necessary to produce a painting that exemplifies:

Nicolas Poussin outlined the principles of classicism and described the essential ingredients needed to produce a painting that exemplifies balance, purity and rigor in form, lines and proportions.

Explanation:

Nicolas Poussin was the greatest name associated with classicist painting of his time, being the artist who delimited many concepts associated with this aesthetic period in art. According to Poussin's paintings, classicism should represent purity, precision, balance and rigor in the representation of lines, angles, shape and proportions. His paintings had as their main focus the representation of nature in a realistic and charming way, however, the rigor and precision of the drawings was also seen in the way he drew the human body and any other element in the real world.

a chromatic scale uses the twelve tones of the octave, while a regular scale only uses eight, or seven different notes (as the first note is played twice)

the previous answer given.