Chanda is one of the six auxiliary sciences of Vedas
(Vedanga). Chanda Shastra is the science of metrics or prosody. There is a long
textual tradition of prosody in Sanskrit. Sages such as Ashvalayana,
Sankhayana, and Apastamba have formulated the rules governing the Vedic meters
and arrange them in aphorisms to facilitate easy application of rituals. The
later classical meters were developed from Vedic meters. Pingala systemized the
science of meters.
Gayatri, usnika, brihati, pankti, anstupa (used in Valmiki’s
Ramayana), tristubha, and jagati are some of the most popular meters in Vedas.
Gayatri has three lines of eight syllables each. Many of the
others have four feet each. In classical Sanskrit, anustup is the most popular
meter; it has several variations. In the case of long meters, yati – a pause –
is introduced for rhythmic pronunciation.
The meters are broadly classified as sacred vaidika chandas
and general or literary laukika chandas. A verse in which the meter may be
regulated by the number and position of syllables in each pada (quarter) is
known as vritta, and that in which the meter may be regulated by the number of
syllable instants in each quarter is jati.
The last syllable of a quarter is understood as long or
short depending on the exigencies of the meter. Writers on prosody have recognized
eight syllabic groups ya, ra, ta, bha, ja, sa, ma and nagana (foot), each
consisting of three syllables and distinguished from one another by a
particular permutation of long or short syllables.
Gayatri, consisting of three quarters, is an example of the
group of meters used in sacred hymns. It is the meter of the opening hymn of
Rig Veda. There are twenty six classes of meters, each comprising a great
number of possible syllable groups. The total possibilities may be several thousand
out of which only about fifty have been popularly used.
Some later works on prosody are Bharata Muni’s Natyashastra,
Varahamihira’s Brihata Samhita, Kedarabhatta’s Vritta Ratnakara, Hemachandra’s
Chandonusasana and Ksemendra’s Suvrttalika.