Sixteen matras in four vibhags of four — clap on 1, 5, and 13, wave on 9. This is the default cycle of Hindustani music: the tala of most tabla solos, sitar and sarod gats, drut khayal, and the bulk of the kaida-tukra repertoire.
Its symmetry is its power: the khali on 9 divides the cycle into balanced halves, so phrases map onto it with maximum clarity. Everything from a first theka to the most intricate chakradhar arithmetic is normally learned here first. The theka's open half turns closed at "Dha Tin Tin Ta," the khali announcing itself unmistakably.