Here is your short paragraph on Gajan:
This is an elaborate annual (or occasional) ceremony of Dharma worship in the Burdwan division of West-Bengal and is continued for twelve days. This is celebrated in other places of Bengal also.
Literally Gajan means shouts (garjana). The Carak worship of Siva is held on the last day of the Bengali year.
In some places, the asserts wander from one village to another carrying the idol of Shiva and sings loudly in praise of the god. They hault at every village and receives alms from the villagers.
During Gajan, Lord Shiva or Dharmaniranjan is invoked by loud sound. The festival also marked by, song and varied dances by the ascetics. At grand level, this is observed in the villages of Bankura and Burdwan like Panchal; Kudmun respectively. At Howrah, Hoogly and at Tarakeshwar of Medinipur district. Also well-known is Kandi’s ‘Rudra dever Gajan’.
Gajan is also held in honour of folk deity Dharmaraj Thakur in many places of Bengal. Particularly mention could be made of Gajan Mela of Manteshwar, a village near Kalna of West-Bengal held every year during Baishakhi Purnima.