Bakersfield is a city in and the county seat of Kern County, California, United States. The Bakersfield–Delano Metropolitan Statistical Area, which includes all of Kern County, had a 2010 census population of 839,631, making it the 62nd-largest metropolitan area in the United States. The more built-up urban area that includes Bakersfield and areas immediately around the city, such as East Bakersfield, Oildale, and Rosedale, has a population of over 520,000. Bakersfield is a charter city. The city is a significant hub for both agriculture and oil production. Kern County is the most productive oil-producing county and the fourth-most productive agricultural county (by value) in the United States. Industries include natural gas and other energy extraction, aerospace, mining, petroleum refining, manufacturing, distribution, food processing, and corporate regional offices. The city is also the birthplace of the country music genre known as the Bakersfield sound.