Gat is the instrumental equivalent of bandish — a short, fixed melodic composition that anchors an instrumental performance after the alap, jor, and jhala have established the raag. While vocal music uses bandish (with text), instrumental music uses gat (without text, since the instrument doesn't sing).
A typical gat has two parts, sthayi (the lower-register theme) and antara (the higher-register answering theme), parallel to bandish structure. The gat is performed in a specific taal, accompanied by tabla, and serves as the melodic ground around which the artist improvises taans, layakari, and tihais — returning to the gat between each improvisation, with both soloist and tabla aiming for sam (the first beat).
There are two principal gat traditions on the sitar and sarod: **Masitkhani gat** (slow, attributed to the 18th-century Masit Khan) and **Razakhani gat** (fast, attributed to Reza Khan). Masitkhani gats are typically in vilambit or madhya laya; Razakhani gats are in drut. A complete performance often features both — first a Masitkhani in slow tempo, then a Razakhani in fast tempo.
The gat repertoire is gharana-bound: each instrumental lineage carries its own treasury of gats, passed down from guru to disciple. Choosing which gat to play is itself a statement of lineage.