ASA, one of the thirty one ragas or musical measures into which compositions comprising the Sikh holy book, Guru Granth Sahib, except the Japu, are cast and in which they are meant to be recited and sung. This raga is important in the Sikh system of music, and is said to have developed from the tune of a folk ballad Tunde Asraje di Var prescribed as the musical key for singing the Sikh morning liturgy, Asa ki Var.Asavari and Asa Kafi are two subsidiaries of Asa employed in the Guru Granth Sahib. Also, more appropriately, it is assigned to the cold season and is meant to evoke a calm mystical mood.
KIRTAN (from Skt. kirii, i.e. to praise, celebrate or glorify), a commonly accepted mode of rendering devotion to God by singing His praises, is a necessary part of Sikh worship. Music plays a significant role in most religious traditions. In Sikhism it is valued as the highest form of expression of adoration and counts as the most efficacious means of linking the soul to the Divine Essence. Kirtan in the Indian tradition can be traced back to the Vedic chant in the second millennium B.C., the impulse behind it being the realization of the effect on the individual of joining the sound of music to the religious text.