The elements of art are line, shape, form, texture, value, space, and color. The principles of design (also called the principles of art) are balance, harmony, contrast, emphasis, movement, repetition, rhythm, proportion, and unity.
In short, elements are things that make the design. Principles are rules, guidelines, and philosophies, that govern the design.
I believe it’s perpendicular but let me know if I’m wrong:)
Pianissimo has the abbreviation of *pp*, representing that it is “double-piano”, as with fortissimo, which is *ff*.
Pp