Staff
A set of five, equidistant, horizontal lines joined together by a brace. The staff (also called stave) is used to clearly communicate musical notation. Note symbols, dynamics, and other performance directions are placed within, above, and below the staff.
Line
An interval located between two spaces on a staff.
Notation
Visual symbols for sound. The most common notation is the fixed treble and bass clefs with modern pitch notation therein. The notation of music has undergone several transformations since the first visual symbols for music were invented, c. 500 B.C.
Dynamics
The loudness or softness of a composition. The term piano (p) is used to indicate softness and forte (f) to indicate loudness. Each of these is augmented if the letter symbolizing it is doubled or tripled (e.g. "pp" - "pianissimo", "very soft"; "ppp" - "pianississimo", "very, very soft"). Each is also lessened if proceeded by mezzo (m) (e.g. "mf" - "mezzo forte", "somewhat loud"). Also included in dynamics are the crescendo ("slowly growing louder"), decrescendo ("slowly growing softer"), and the sforzando ("sudden loudness").