In music, melisma is the technique of changing the note (pitch) of a single syllable of text while it is being sung. Music sung in this style is referred to as melismatic, as opposed to syllabic, where each syllable of text is matched to a single note. Music of the ancient cultures used melismatic techniques to achieve a hypnotic trance in the listener, useful for early mystical initiation rites (Eleusinian Mysteries) and religious worship. This quality is still found in much Jewish, Hindu and Muslim religious music today. In western music, the term most commonly refers to Gregorian chant, but may be used to describe music of any genre, including baroque singing and later gospel. Within Jewish liturgical tradition melisma is still commonly used in the chanting of Torah, readings from the Prophets, and in the body of the service itself. For an examination of the evolution of this tradition, see Idelsohn.Melisma first appeared in written form in the system of Torah chanting develope
Source:
http://en.wikipedia.org/wiki/Melisma