The mexican was intended to address mexico's need for a national and revolutionary art.

The answer is

Mexican Muralism

Explanation:

Mexican muralism was a movement and promotion of mural painting starting in the 1920s with social and political messages as part of efforts to unite the country under the post Mexican Revolution government. It was headed by “the big three” painters, Diego Rivera, José Clemente Orozco and David Alfaro Siqueiros.

pitch- the definition of pitch is as follows:

"the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone."