City governments and all the secondary offices, boards, committees and commissions of a city are creations of the law. They find their origin in either the Tennessee Constitution or statutory law. It is a long-established principle in Tennessee law that municipalities can do only those things that the law authorizes them to do. Therefore, it is vitally important to any operation of city government to know what the laws are that authorize the city to perform a function and to know what the laws are that place limitations around that authority. There are laws that require cities and all local governments to keep records and laws that govern how a city manages its records. Both of these topics are examined in this section.
 Barnes v. City of Dayton, 216 Tenn. 400, 392 S.W.2d 813 (1965)