A bell unit of a portable bell system, including a support structure, a plurality of bells mounted on the support structure, a bell shell including a plurality of segments, at least one of which is displaceable to allow a size change of the bell unit. The bell shell is configured to be in a first position when the plurality of segments form a shell that is of a shape of a bell, and hangs over and partially encloses the support structure and the plurality of bells, and is in a second position when the at least one segment is displaced to effectuate the size change.