Melody is the horizontal dimension in music, while harmony adds perspective.

Melody is the succession of single tones or pitches perceived by the mind as a unity.  Melody is the horizontal dimension in music, while harmony adds vertical perspective. Chords are the essential part of harmony. The harmony is the "vertical" relationship between simultaneous chords. So, harmony is the "vertical aspect" of music and melody the "horizontal".

The linear perspective changed the quality of art because it gave art a sense of reality. it gave the illusion that the background and surroundings were actually close and/or far and a sense of depth. linear perspective change the quality of art following its birth the renaissance period as they want the art to be more realistic and they believe one way to achieve it is to use the method of linear perspective. it uses the principle of math to realistically portray space and depth in art.