A contemporary Carnatic music concert (called a kutcheri) usually lasts about three hours, and comprises a number of varied compositions. Carnatic songs are composed in a particular raga, which means that they do not deviate from the notes in the raga. Each composition is set with specific notes and beats, but performers improvise extensively. Improvisation occurs in the melody of the composition as well as in using the notes to expound the beauty of the raga.
After singing the opening kriti, usually, the performer sings the kalpanaswaram of the raga to the beat. The performer must improvise a string of swaras in any octave according to the rules of the raga and return to beginning of the cycle of beats smoothly, joining the swaras with a phrase selected from the kriti. The violin performs these alternately with the main performer. In very long strings of swara, the performers must calculate their notes accurately to ensure that they stick to the raga, have no awkward pauses or lapses in the beat of the song, and create a complex pattern of notes that a knowledgeable audience can follow.
Performers then begin the main compositions with a section called raga alapana exploring the raga. In this, they use the sounds aa, ri, na, ta, etc. instead of swaras to slowly elaborate the notes and flow of the raga. This begins slowly and builds to a crescendo, and finally establishes a complicated exposition of the raga that shows the performer's skill. All of this is done without any rhythmic accompaniment, or beat. Then the melodic accompaniment (violin or veena), expounds the raga. Experienced listeners can identify many ragas after they hear just a few notes. With the raga thus established, the song begins, usually with lyrics. In this, the accompaniment (usually violin, sometimes veena) performs along with the main performer and the percussion (such as a mridangam). In the next stage of the song, they may sing niraval or kalpanaswaram again. 2b1af7f3a8