alap, in the art musics of South Asia, improvised melody structures that reveal the musical characteristics of a raga. Variant forms of the word—alap in northern Indian music and alapana in Carnatic music (where the term ragam improvisation is also used)—are often found.
Alap ordinarily constitutes the first section of the performance of a raga. Vocal or instrumental, it is accompanied by a drone (sustained-tone) instrument and often also by a melodic instrument that repeats the soloist’s phrases after a lag of a few seconds. The principal portion of alap is not metric but rhythmically free; in Hindustani music it moves gradually to a section known as jor, which uses a rhythmic pulse though no tala (metric cycle). The performer of the alap gradually introduces the essential notes and melodic turns of the raga to be performed. Only when the soloist is satisfied that he has set forth the full range of melodic possibilities of the raga and has established its unique mood and personality will he proceed, without interruption, to the metrically organized section of the piece. If a drummer is present, as is usual in formal concert, his first beats serve as a signal to the listener that the alap is concluded.