Great minds have noted that many phenomena occurring in human surroundings have a cyclical movement i.e. a movement ends where it starts from. To give an example – Tintaal played on tabla completes its cyclical movement at a point from which the tala starts a new cycle.
To further support this contention, we could take example of vocal bandishes. By and large, these bandishes have 4 lines namely mukhda, manjha, antara and amad. Usually, the mukhda comprises of the essence of the raga swaroop, while the manjha goes down into lower octave. The antara takes the melody to upper Sa and amad brings the melodic cycle back from where the mukhda started, completing a cycle. Sitar gats, both vilambit and drut, also follow the same structure.
To further elucidate this concept, the development of alap in vocal music and now followed by instrumentalists of specific gharanas, has a cyclical pattern. To illustrate – there are four stages in alap development – namely sthayi, antara, sanchari and abhog. As we all know, sthayi is concerned with melodic development from lower octave up to the midpoint of the scale, while antara is concerned with the development from midpoint to upper octave. Sanchari (following dhrupad discipline) covers movements through phrases interspersed with sweeps. The melodic movement is played at slightly faster pace than the alap covering all these sections. Abhog, the last section, is designed to bring melodic movements from the upper octave to the lower octave – called amad in musical language. Thus, it is noted that, alap starts in sthayi portion followed by antara and sanchari, and ends with amad, which completes a cycle.