Indian music evolved on melodic lines and has reached points of tremendous sophistication, which are unsurpassed in the world even today. Melodic aspects are the main anchor points of Indian music but it is balanced with the rhythmic aspects in an admirable manner. Carnatic music believes in the maxim "Srutir mata, layah pita" (Melody is Mother, Rhythm is Father). The implication is that music is created only out of the union of the two. All the aspects of raga, melody and aesthetics have been dealt with here.
Carnatic music is a melody-based system. The stress is on successive combination of notes unlike some systems, where one comes across the concept of harmony. Harmony involves rendering more than one note at a time. The melodic aspects of Carnatic music are very easy to understand as they are very systematic in their development from the simple to sophisticated. Melody in the context of Carnatic music may be explained as, "The production of any musical tone or succession of such tones or semitones, with definite frequencies, within certain parameters, whether rendered independently or in conjunction with rhythm and / or lyrics".
In Carnatic music the term Nada has found a special place. It refers to sounds that are pleasing to the ears, as opposed to noise. Nada, according to ancient Vedic texts, Upanishad and Purana, is the easiest path to elevate oneself and attain salvation. This in turn, is the core of Hindu philosophy. Tyagaraja and such other great composers echo the same sentiments in many of their compositions like Nadasudharasam, Nadatanumanisam etc., besides prescribing the scientific production of musical sound (e.g., Sobhillu Saptaswara).
There is another school of thought that believes that music itself is divine and that the perfect synchronisation of the performer with the musical sound, Nada (the practice of which is called Nadopasana), is the real divine bliss.
For sound to fall in the category of the musical, the vibrations have to be regular. Thus, evenly spaced vibrations whose frequency determines the 'highness' or 'lowness' of the sounds create musical tones. This factor is called Pitch. We come across people talking about 'high-pitched screams' or 'low-moaning sounds'. Similarly they can distinguish between high and low frequency notes when they hear music.
In Carnatic music, Pitch is of central concern. Every individual has a natural pitch, a level or range at which he can produce notes of best quality with ease. Generally, male voices are lower in pitch than female voices. The marked difference in voice quality among men, women and children is due to the size of the vocal chords, the kind of breathing and the physical make-up of the resonant cavities. Talking of tonal comfort, at the natural pitch level of an individual the vocal chords are in a relaxed and almost flaccid condition. In the case of instruments, the fundamental pitch is fixed based on the length, construction and timbre of the instrument.
The fundamental key to pitch selection is the basic tonic note, Sa, called the Adhara Shadja. Every other note is in relation to this note, unlike the Western classical system. This becomes the fixed pitch and is called the Sruti. Maintaining this fundamental pitch throughout is of utmost importance. This has been beautifully encapsulated in the Sanskrit maxim, "Srutir mata" which accords pitch the status of Mother.
When the frequency of any note is exactly doubled, a . In Carnatic music, a range of three octaves is generally used. They are called the Mandra, Madhya and Tara Sthayi, referring to the lower, middle and higher octaves respectively.
Many music systems have divided an octave into twelve parts or notes. The melodic interval between two successive notes is called a semitone and that between alternate notes is referred to as tone. One can imagine a semitone to be half a step and tone to be one whole step.