California was settled by Roman Catholic missionaries from Spain who built structures that served both as military forts and churches up and down the Pacific coast called "missions". Many cities in California like San Francisco got their start as a Mission. Many of these are still standing and the bells in the towers ring to mark time and call people to prayer. The song refers to the chiming of one of these mission bells. There are 21 missions in all here's a link that will show you some pictures of them: http://www.missionart.com/photo-main.html