In addition to normal activation, markers can also be activated by using “chains”. If two markers overlap, and one of them is successfully activated, the second marker will become “reserved”. Reserved markers play automatically, without any player action. A reserved marker will also reserve any markers touching it. Thus, by activating one of several overlapped markers, players can form a chain of reserved markers. A player can also create a “chord” by activating two or more non-touching markers at the same time.