<P> Mostly instrumental pieces creating sounds of a soothing, romantic, mood - elevating or generally relaxing nature . Steven Halpern's Spectrum Suite, released in 1975, is generally credited as the album that began the new - age music movement . </P> <P> The polka, which first appeared in Prague in 1837, continued to be a popular form of dance music through the 20th century, especially in Czechoslovakia, Poland, and areas of the United States with a large population of central - European descent . A particularly well - known 20th - century example is Jaromír Vejvoda's Modřanská polka (1927), which became popular during World War II in Czechoslovakia as "Škoda lásky" ("A Waste of Love"), in Germany as the Rosamunde - Polka, and among the allied armies as the Beer Barrel Polka (as a song, known as "Roll out the Barrel"). In the United States, the "Eastern style" Polish urban polka remained popular until about 1965 . Polka music rose in popularity in Chicago in the late 1940s after Walter' Li'l Wally' Wallace Jagiello created "honky" polka by combining the Polish - American rural polka with elements of Polish folksong and krakowiak . A later, rock - influenced form is called "dyno" polka . </P> <P> Rock and roll developed from earlier musical forms including rhythm and blues, which had earlier been called race music, and country music . See also rock musical and rock opera . </P> <Table> <Tr> <Td> </Td> <Td> "Gloria: In Excelsis Deo / Gloria" song by Patti Smith, an example of early punk rock . </Td> </Tr> <Tr> <Td_colspan="2"> Problems playing this file? See media help . </Td> </Tr> </Table>

Who combined their love of music and technology