Intrumental Music :
Instrumental Music occupies an important position in Indian music. The three-fold aspects of "Sangeet" are Vocal Music [Gayan], Instrumental Music [vadan], and Dance [Nritya], and has a very ancient history. Instrumental Music is known as "Vadhya Sangeet". Indian Instruments have either of the three main functions. There is the Melodic Function, there is a Rhythmic Function, and there is the drone for Eg: Sitar is a Melodic Instrument, Tabla is a Rhythmic Instrument, Tanpura is a Drone. The Melodic Instruments follow the vocal styles [Gayaki Ang] and also can played Instrumental Style [Tantrikari Ang] linked to the dynamics of the Instrument.
Dynamics is the nature of the loudness of an Instrument meaning the amplitudinal characteristics of the Instrument. Depending on the nature of the instrument for Eg: the Sitar and Flute offer a good illustration. A flute has continuity, therefore there is a steady sound as long as the breath is applied. Since it is possible to sustain a sound for a long time, it is possible to perform all kinds of delicate Meends [Glissando], Gamaks [Ornamentation]. Instruments with a long sustain tend to follow the vocal styles in their presentation. Contrast this to a Sitar with its rapid decay. The sound is essentially inaudible within a few seconds. Hence the Instrumental styles known as: Alap, Jor, Gat and Jhala is played. The Alap is a slow rhythmless elaboration upon the Raag. The Jor is a section that has rhythm but no developed rhythmic cycle (i.e., Tal). The Gat is the fully developed piece, while the Jhala is a fast rhythmic interplay between the drone strings and the main playing strings.