Literally a "torrent": a form built from small rolling cells — Tirekite, Dhere Dhere, TakaTaka — cycled and permuted at high speed into a continuous stream of sound. Some relas are developed like fast kaidas with theme and variations; others serve as freewheeling display.
The form rewards evenness above all: at full tempo individual strokes fuse, and any imbalance reads as stutter. Relas typically arrive late in a solo as the velocity peak, and Benares and Farrukhabad lines are especially rich in them. A rela slowed down should still be immaculate — that is the standard test.