As with everything created by humans, there is an elemental basis for the composition of music. The basic essence of music lies with its harmony, rhythm, melody and dynamics. Harmony is the relation of notes to notes as they are play simultaneously. Rhythm, by the most simple definition, is musical time. Melody is a musical line of single tones or pitches, heard by the listener as a single unity. Dynamics provide the emotion behind the musical thought. Dynamics tell the performer when to play a piece softly or when to play loudly--music ranges from a mere whisper to the fullest of sound.