The Sikhs, who mostly belong to Punjab, form a sizable group of Indian population. The orthodox Sikhs believe that their religion was revealed by God to Guru Nanak, whose spirit entered the second and the subsequent gurus till the tenth Guru. Guru Gobind Singh, ordained the Sikhs to treat the Adi Granth, popularly known as the Guru Granth Sahib, as their Guru.
But the students of history and religion think that the seeds for the birth and growth of this religion were present in the Bhakti movement, in its nirguna branch. The Sikhs basically believe in a formless God, equality of all mankind, need of a guru and the pahul tradition.
The fifth guru, Guru Arjun Dev, gave the Sikhs three things. The first was in the shape of the Adi Granth, which contains the sayings of five gurus and other allied saints. The second was the standardised script for Gurmukhi in which the Adi Granth was first written. And finally, the site and the foundation of the Har Mandir sahib or the Golden Temple and the Akal Takht at Amritsar, the highest seat from where the dictats for the entire Sikh community are issued.
The tenth guru, Guru Gobind Singh created the Khalsa, which means "the pure", in 1699. He also ordained the Sikhs to take five vows, namely, keeping of kesh (long hair and a beard), kangha (comb), kada (a metallic bangle), kirpan (a sword) and kaccha (an underwear extending to a little above the knees). Consequently, these symbols became the distinguishing marks of a Sikh. He further added that after his death the Adi Granth will be the guru of the Sikhs and they have to pay obeisance to this holy book.
Music has always been an important feature of Sikhism and they believed that through music one can attain ecstacy or samadhi.