St. Petersburg, Florida $10 million investment plan which helped build the St. Petersburg City Hall. By the 1940s the city received a large population growth due to World War II. St. Petersburg was a training ground area for the U.S. Coast Guard who had a training base and used the city's Bayboro Harbor, and for the Army Air Force who was selected by the War Department to use the city as their technical service training station. With both stations occupying the city, more than 100,000 troops occupied all hotels in St. Petersburg. After the war, most troops who were stationed in St. Petersburg
20th-century music had earlier been called race music, and country music. See also rock musical and rock opera. 20th-century music During the 20th century there was a huge increase in the variety of music that people had access to. Prior to the invention of mass market gramophone records (developed in 1892) and radio broadcasting (first commercially done ca. 1919–20), people mainly listened to music at live Classical music concerts or musical theatre shows, which were too expensive for many lower-income people; on early phonograph players (a technology invented in 1877 which was not mass-marketed until the mid-1890s); or by individuals performing music