This resurgence of bluegrass has also seen the rise of the 'newgrass' phenomenon, with artists such as Dan Crary, Tony Rice, Jim Lauderdale and Larry Cordle showing just how technically brilliant this essentially simple form of music can be.Willie Nelson and his famous nylon string acoustic (Credit: Tim Mosenfelder/Corbis)In the 1950s and 60s, country was taken over by the crooners.