Since the Tala (rhythm) is fixed, accelerating the tempo implies that with each acceleration, the singer has to compress more and more syllables in a Matra (beat or a unit of time). With each shift in Laya from Duguna, Tiguna, Chauguna and so on, the fact of compression of an increasingly larger number of syllables in the same unit of time creates for the listener an illusion of increasing speed of Tala even though the Tala remains the same. The ability of the performer to change the tempo in precise multiples, demands, on the part of the performer, a perfect control of his delivery and a very precise sense of the beat. Such a feat is not easy of accomplishment and that is why traditionally the Dhrupad style laid much emphasis on this capacity called Layakari. A performer who could demonstrate this in ample measure and in perfect precision, easily and justifiably earned the admiration of his audience.
Generally in a Dhrupad performance, the singer begins his Alapa in Thaha. This, being the basic Laya and therefore the slowest, is also called Vilambita Laya, literally the slow tempo. This Laya lasts for a variable period depending on the mood of the singer and the audience. It usually lasts for five to twenty minutes. Step by step the singer, while still in alapa, moves to faster and faster Layas. The farthest range of the Laya reached by the singer is called the Druta Laya and any other Laya or Layas in between the Thaha and the Druta Laya is called Madhya Laya. Having reached the fastest Laya -the Druta Laya- the singer returns to the Thaha as it is customary to end the Alapa on this Laya. After the Alapa the singer takes up the composition and repeats a similar sequence of Layakari - starting from the Thaha and going eventually to the fastest Laya that he is capable of demonstrating. Depending on the level of sophistication of the artist, he demonstrates a large or small display of Layakari. In the entire performance, care is taken to maintain perfect harmony with the drum so that both the singer as well as the drummer arrives at the Sama at exactly the same point of time.
In addition to the Layakari, there is yet another art which the Dhrupad singer demonstrates and this is called Bolabanta. Bolabanta is the art of singing piece by piece, small phrases of the text in different tonal combinations and in different Layas. Bolabanta is a Hindi word meaning 'parcelling out of the phrases (of text)' and in Bolabanta this is precisely what the singer does. In this process he brings in an immense charm and variety in his singing.