Musical note indicated by placing the symbols in the key signature, which then apply implicitly to all occurrences of corresponding notes. Explicitly noted accidentals can be used to override this effect for the remainder of a bar. A special accidental, the natural symbol , is used to indicate an unmodified pitch. Effects of key signature and local accidentals do not accumulate. If the key signature indicates G, a local flat before a G makes it G (not G), though often this type of rare accidental is expressed as a natural, followed by a flat () to make this clear. Likewise (and more
Music of southern China Perfect-fourth transposition of the melody ("fan") also occurs, though the tonal centre remains constant. Four or five main modes ("diao") are traditionally identified. However, while elsewhere in China such modes are mainly defined by absolute pitch and by the degree of the pentatonic scale that is taken as the key-note (thus setting the intervals of the scale), the xianshi conception of mode, rather like the Indian raga system, includes motif, ornament and intonation. Pitch is not absolute but the scale is usually constructed on a key-note approximating to western concert F – F#. Modes are pentatonic but all derive from