Corporate communications emerged as a distinct function within large corporations in the 1970s after periods of economic crisis. It combines elements of public relations, marketing, and advertising to strategically communicate an organization's messages internally and externally. Some pioneers who helped develop corporate communications as a management function include Paul Garrett at General Motors and Harold Burson at AT&T. A key role of corporate communications is to build relationships between a company and its various stakeholders through coordinated, ethical communication efforts.