Gurbani, also known as kirtan, is one of the purest forms of devotion. They are sung by Sikh people. It is actually ‘gur ki bani’, which means teaching of Guru Granth Sahib Ji.
Guru Granth Sahib Ji hymns were written by Sikh gurus: Guru Nanak, Guru Angad, Guru Amar Das, Guru Ramdas, Guru Arjan, and Guru Tegh Bhadur. It also contains teachings from thirteen Hindu saint poets and two Muslim saint poets.
Gurbani is composed of a total of 60 ragas, out of which 31 are single ragas and 29 are mixed ragas. Every chapter starts with Assa Raag, except Japji Sahib, which is morning prayer. Some of the bani are also recited from Dasam Granth written by the 10th guru, Guru Gobind Singh .
The musical journey in Sikh history was started by Guru Nanak Dev and his companion Bhai Mardana who accompanied Guru Nanak Dev in his journey. Bhai Mardana was born in a Muslim family in Talwandi, Nankana Sahib, which is now in Pakistan.
Bhai Mardana had an immense knowledge of music and used to play melodious rabab. It is said that he used to sing deep from his throat and played rabab while practising kirtan. He also used to sing hymns written by Kabir Das, Ravi Das, Dhanna, Beni and Trilochan.
Bani recited by professionals (raggi) is always in ragas with seven sur, but there is no hard and fast rule for a devotee to sing within the ragas; they can choose an easy way and recite it in their own manner.