Jack and his choir were hunting a pig.
When Jack and his choir first marched down the beach they stopped close to the platform and Jack, alone, vaulted onto the platform to speak to Ralph. When Ralph explained that they were having a meeting and said, "Come and join in." The choir began to scatter from close line. Jack shouted, "Choir! Stand still!" The choir obeyed.
Ralph likes Jack. He also notices that Jack knows what his doing and decides that Jack wouldn't be too good as an enemy. As a way to satisfy Jack's urge to control, Ralph offers the choir to Jack.
Ralph takes Simon and Jack along with him on the expedition.
Jack and his choir became hunters and helped Ralph and the others hunt for food on the island. However, they eventually broke away from Ralph's leadership and formed their own tribe, leading to a violent power struggle.
When Ralph is elected to be chief he knows Jack is dissapointed (as Jack also wished to be chief) so he appoints Jack as leader of the choir and asks him what he wants them to be, to which Jack replies, "hunters."
He puts Jack in charge of the choir and asks Jack what he wishes them to be, to which Jack replies "Hunters."
When the boys elect Ralph as leader, in favour of Jack, Ralph puts Jack in charge of the choir and asks him what he would like them to be. Jack replies, "Hunters."
When Ralph is initially elected leader he confirms that the choir still belongs to Jack. Jack says that he wants his choir to be hunters, to supply the boys with meat by hunting pigs. After they light a signal fire on the mountain Jack says that his hunters will take on the responsibility for keeping the fire lit.
After Ralph won the election to be chief, leaving jack as the losing candidate, Ralph placed Jack in charge of the choir and allowed Jack to choose what he wished them to be. Jack chose, "Hunters."
Ralph told him he could be the leader of the choir boys and then he made his own group of only himself until people from Ralph's side went to Jack's side. :)
Jack is the leader of the choir and the one who leads the break away group, who split from Ralph's lot to form a tribe.
The choir wear shorts and shirts, a box shaped black hat with a silver badge (Jack's badge is gold as he is the choir leader). They also wear a long black cloak, which has a silver cross on the breast and a ruff around the neck.