The phrase "harmony is vertical" means that                a.  harmony involves notes that sound at the same time.      b.  harmony includes every note in an octave.      c.  the singers in a harmony improvise notes from up and down a scale.      d.  notes in a harmony only increase in pitch.

To make an etching the artist first coats the entire printing plate with an acid-resistant substance called a made from beeswax, asphalt, and other material. the artist then draws on the coated plate with an etching needle exposing the metal. next the plate is dipped in the plate is removed, the waxy coating removed, and the plate is cleaned, inked and printed.

Match these items. match the items in the left column to the items in the right column. 1. aesthetics in art, a technique for defining shape, also used to create a sense of depth 2. composition a perceived line that describes three-dimensional form 3. contour line a method of presenting an illusion of the three-dimensional world on a two-dimensional surface 4. line (pronounced "uhvrr") — a work of art; the sum of the lifework of an artist, writer, or composer 5. oeuvre the way an artist organizes forms (lines, shapes, etc.) in an artwork, either by placing shapes on a flat surface or by arranging forms in space 6. patron the relationship of one part of a person, building, or object to another; for example the size of a statue's head in relationship to the rest of the body 7. personification the study of beauty or good taste; anything related to the study of beauty or good taste 8. perspective giving human characteristics to something that is not human 9. proportion generally a wealthy person who pays an artist to create a work of art; throughout much of history artists could not have survived without "patronage" 10. symbol an object or word or gesture that represents something else

I’m a paragraph of no less than 125 words, explain the single most important factor involved in advancing american classical music in the twentieth century.