Arrange the group in a circle seated on chairs. Each person/child should have their own chair. All the presents should be handed out, one to each child. Then music is played from a tape deck etc. and suddenly stopped randomly. The birthday child then opens whichever present he/she is holding when the music stops. If their are more presents than children, a new present can be put into the circle after the last one is opened. The parents can time the music so that the birthday child opens a present each time the music stops.