Strings, particularly the violin, began gaining popularity outside of classical music during the 20th century with the emergence of jazz and country music in the United States. Notable early string musicians included old time fiddlers in the South like Bill Hensley and Asa Helton who competed in the 1920s-1940s. Western swing also rose in popularity during this time led by groups like Bob Wills and his Texas Playboys. In the latter half of the century, Irish fiddlers Liz Carroll and Martin Hayes emerged, as did the innovative Turtle Island String Quartet in the 1980s, the first commercial string quartet known for stretching musical boundaries.