What characteristic do two tones of diffrent pitches that are an octave apart have?

What concern was incorporated into western art during the industrial revolution? a. the depiction of picturesque scenes b. the criticism of religion c. the nobility of entrepreneurs d. the plight of working people

Science always prove or disprove their explanations by

Judy pfaff’s installations combined different art forms to express her unique vision of the world. which is not an art form pfaff integrated into her installations? !