(Yamaha Products). The Yamaha Guide to Sound Systems for Worship is written to assist in the design, purchase and operation of a sound system. It provides the basic information on sound systems that is most needed by ministers, members of boards of trustees and worship and music committees, interested members of congregations, and even employees of musical instrument dealers that sell sound systems. To be of greatest value to all, it is written to be both nondenominational and "non-brand-name."