Two notes played together, usually in one hand but sometimes in both, whose distance is the interval of a 2nd of any quality.
A type of articulation indicating the player to play smoothly and seamlessly, with the notes slightly overlapped.
Octave Higher and Octave Lower
Symbols that indicate playing a note or range of notes either an octave higher or lower than notated.
An indication instructing the player to play very softly; softer than piano.