Traditionally most musical system have 7 basic symbols for notes. Carnatic Music uses 'sa,ri,ga,ma,pa,da,ni' and western music 'C,D,E,F,G,A,B', these being in ascending pitches. After 'ni' and 'B' the symbols are repeated again (with some additional indications for the octave) to signify the similarity or repetition in music. Practically all Carnatic music is restricted to 3 octaves and in notation written in Tamil or Telugu (and in some English notation also) a dot over the symbol indicates upper octave (Thaara Sthaayi) and a dot below the symbol the lower octave (Maandhra Sthaayi) and notes without any dots are in the middle octave (Madhya Sthaayi ). An example of the Tamil notation is given below
The notes with the same symbols in different octaves are said to belong to the same 'pitch class'.
However, in Carnatic Music whatever pitch (or frequency) is chosen as Aadhaara Sruthi, it gets the symbol 'sa' unlike the Western system where the symbols have absolute pitch values and are not changed when the 'key' is changed.
To avoid using special fonts in these web pages, notes in the middle octave are written in lower case as 'sa,ri,..'. Notes in upper octave as 'Sa,Ri,Ga...' and notes in lower octave as 'mA,pA...'. The same system is used in Gaayaka program (of Rasika software) which plays notation from notes typed in the Carnatic Style.
As explained in the next page, though only 7 symbols are used, actually most systems have 12 notes (of approximately equal intervals) in an octave and additional symbols are used in Wesetern music to indicate them like C# (C-sharp) or Gb (G-flat). In Carnatic Music the variations are known by the 'Melam' to which the 'Raagam' of the current composition belongs.