when was this kind of music first recorded?
1917 - 1920's.
American popular music
Many popular standards, such as "The Good Old Summertime", "Shine On Harvest Moon", and "Over There" come from this time. There were also a few early hits in the field of jazz, beginning with the Original Dixieland Jazz Band's 1917 recordings, and followed by King Oliver's Creole Jazz Band, who played in a more authentic New Orleans jazz style.

Blues had been around a long time before it became a part of the first explosion of recorded popular music in American history. This came in the 1920s, when classic female blues singers like Ma Rainey, Bessie Smith and Mamie Smith grew very popular; the first hit of this field was Mamie Smith's "Crazy Blues".
who is usually considered the first important composer of american popular song Stephen Foster.
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American popular music [SEP] Early recorded popular music
Thomas Edison's invention of the phonograph cylinder kicked off the birth of recorded music. The first cylinder to be released was "Semper Fidelis" by the U.S. Marine Band. At first, cylinders were released sparingly, but as their sales grew more profitable, distribution increased. These early recorded songs were a mix of vaudeville, barbershop quartets, marches, opera, novelty songs, and other popular tunes. Many popular standards, such as "The Good Old Summertime", "Shine On Harvest Moon", and "Over There" come from this time. There were also a few early hits in the field of jazz, beginning with the Original Dixieland Jazz Band's 1917 recordings, and followed by King Oliver's Creole Jazz Band, who played in a more authentic New Orleans jazz style.