Answer:
To add tension.
Explanation:
Adding tension in a song makes us feel uneasy or feel like something bad is going to happen. Thus adding suspense to horror or scary songs
The second one is the sfumato technique
Aperture is controlled by 'diaphragm' in optics.
Answer:
Must have four sides, must be able to open and close properly, and must be in the shape of a box.
Explanation:
That is what i could think of.