Jag Gan is a contour of Bengali folk song. This composition has been popularized in Pabna, Rajshahi, Rangpur districts of North Bengal. However, Jag Gan (song) is also popular in Dhaka and Mymensingh. Jag Gan is composed of admiring the indigenes god and pir and the songs are dedicated on the eve of offering Puja and Manat. Muhammad Mansur Uddin has mentioned about the Jag Gan in Pabna District. According to him, shepherd boys, belonging to both Hindu and Muslim, sing Jag Gan' in the night knocking from door to door and express their delight being cooked Shirni (special sweet food cooked with milk, sugar and rice) or arranged feast on Paus Sankranti. The juvenile activities of Krishna and the activities of a group have been absorbed in the Jag Gan of Pabna.
Mansur Uddib has published an extensive narrative in verse entitled by 'Krishna Jag Gan', the part of that is given below:
“O mother, no mercy you offer,
Why do you always say me the thief of butter being my motherFoodgrain
Mother, Keshto goes to Bishnupur, moves Jashoda to the wharf
Gopal enjoys all butter when house is vacant.
Who devoured butter, Lo Gopal, who ate butterFoodgrain
I didn’t take, O mother, Bolai consumed that.
If Bolai would ate- left a bit,
You Gopal ate, left the bowl barren.”
Once the crops of winter are harvested, the peasants pass their leisure. In the mean time, Jag Gan is arranged. The musical program is prolonged whole night round, and the audience enjoys the program. It is presumed that the name 'Jago' (wake up) might be derived from the reality of being awaken all the night round. Alkap gan, Ghatu Gan etc. are also played at night, yet those should not be termed as 'Jag Gan'. To tell its name, special allusions and subjects are associated with. 'Jag Gan' is staged by a group of performers. That means it is a group or team performance. The team consists of 20 members including singer or Gaen, Dohar Nartak or dancer, Musician etc. Juri and Tabla or Drum are used as musical instruments. The force of entertainment is higher due to the supplement of dramatic essences. 'Shak Tola Pala' of Radha, trended in Rangpur, is played with music. In fact, by the name of ' Radha-Krishna',' the story of juvenile of both sexes have so far been' depicted. The legend of Radha 'Krishna has neither highlighted to any affairs of 'picking up vegetables' nor has it depicted any depiction which may resemble to the matter of selling of milk and custard. In the same way, 'The opera of catching fish' is also familiar. In fact, by the metaphor of 'Radha-Krishna', the folk-poet has drawn the picture of real lives around us. Hence, the appreciation of Jag Gan to the mass is huge.'
Apart from the mythological stories of Radha-Krishna, Jag Gan has been enriched with the stories of Pir or religious cleric. Jag of Sona Pir, jag of Sotya Pir (Pir of truth), Jag of Manik Pir, Jago of Gazi Kalu etc. Jag gan in commemoration of Sonaray or Sonapir is also played, which is called 'Jag of Sona Pir'. The sample of North Bengal about Sona Pir is as follows:
Sona Pir uthe bale Manik Pir re bhai,
Esechhi goalpara, Jahir rekhe jai ...
Sona Pir uthe bale Manik Pir re bhai
Merechhi gariber dhan, jiaiya jai.