Defining features of the rockabilly sound included strong rhythms, vocal twangs and common use of the tape echo,[4] but the progressive addition of different instruments and vocal harmonies led to its "dilution".[1] Initially popularized by artists such as Bill Haley, Elvis Presley, Carl Perkins, Johnny Cash, Bob Luman and Jerry Lee Lewis,[5] the influence and success of the style waned in the 1960s; nonetheless, during the late 1970s and early 1980s, rockabilly enjoyed a major revival through acts such as the Stray Cats. An interest in the genre endures even in the 21st century, often within a subculture. Rockabilly has left a legacy, spawning a variety of sub-styles and influencing other genres such as punk rock.