bands, the musicians contribute backup vocals, which typically consist of shouted slogans, choruses, or football-style chants. While most punk rock uses distorted guitars and noisy drumming sounds derived from 1960s garage rock and 1970s pub rock, some punk bands incorporate elements from other subgenres, such as surf rock, rockabilly, or reggae. Most punk rock songs are short, have simple and somewhat basic arrangements using relatively few chords, and typically have lyrics that express punk ideologies and values, although some punk lyrics are about lighter topics such as partying or romantic relationships. Different punk subcultures often distinguish themselves by having a unique style of punk rock, although not every style of punk rock has its own associated subculture. The earliest form of music to be called "punk rock" was 1960s garage rock, and the term was applied to the genre retroactively by influential rock critics in the early 1970s. In the late 1960s, music now referred to as protopunk originated as a garage rock revival in the northeastern United States. The first distinct music scene to claim the punk label appeared in New York City between 1974 and 1976. Around the same time or soon afterward, a punk scene developed in London. Los Angeles subsequently became home to the third major punk scene. These three cities formed the backbone of the burgeoning movement, but there were also other punk scenes in cities such as Brisbane, Melbourne, and Sydney in Australia, Toronto, Vancouver, and Montreal in Canada, and Boston and San Francisco in the United States. The punk subculture advocates a do-it-yourself (DIY) ethic. During the subculture's infancy members were almost all from a lower economic class, and had become tired of the affluence that was associated with popular rock music at the time. Punks would publish their own music or sign with small independent labels, in hopes to combat what they saw as a money-hungry music industry. The DIY ethic is still popular with punks. The New York City punk rock scene arose from a subcultural underground promoted by artists, reporters, musicians, and a wide variety of non-mainstream enthusiasts. The Velvet Underground's harsh and experimental yet often melodic sound in the mid to late-1960s, much of it relating to transgressive media work by visual artist Andy Warhol, is credited for influencing 1970s bands such as the New York Dolls, The Stooges, and the Ramones. Early New York City punk bands were