Many critics believe that while the late 1970s was when punk broke into the public consciousness, the formation of this genre took place a few years before in the recordings of bands such as the Velvet Underground and MC5. These bands were hard to define, but their sound was typically raw, minimalistic and experimental. For example, the Velvet Underground used plenty of feedback in their recordings.
The First Wave of punk consisted of bands in the United States and the United kingdom who took the stripped-down sonic approach of Proto-Punk artists, played their riffs loud and sloppy, and spat in the face of the establishment with their often sneering attitudes and lyrics. In America, the Ramones are often seen as the heralds of the First Wave, while in the U.K., the Sex Pistols led the charge.
New Wave bands appeared in the late 1970s and into the '80s, and tended towards a more polished sound than many earlier punk artists, veering closer to mainstream pop music and finding acceptance on the radio. New Wave bands such as Blondie found fame through the Manhattan CBGB club scene, while in the U.K. the Police became popular. New Wave artists are various in their styles and use of instrumentation; the Human League, for example, incorporated dance rhythms into their music.
Hardcore punk takes the aggression of First Wave punk to new extremes, and began at the beginning of the 1980. Although early Hardcore acts such as Bad Brains utilized loose rhythms, later Hardcore artists began to experiment by tightening up their sound and adding influences from other music genres, such as heavy metal. Hardcore music tends to feature a political consciousness, and lyrics address subjects such as social fears. Famous Hardcore acts include Black Flag, Sick of It All and Fugazi.
A subgenre especially popular in the late 1990s and in the 2000s, Pop-Punk retains punk's penchant for simple rhythms and short songs, but removes much of its aggression and anarchistic stylings, instead focusing on catchy melodies and lyrics that appeal to young people. Bands such as Blink 182 and Sum 41 have enjoyed chart success thanks to this formula, while other artists, including Green Day, retain more of a traditional punk stance while still appealing to mainstream listeners.
Ska-Punk combines the raw energy of traditional punk with the rhythms of the 2-Tone ska movement that appeared in the 1980s, with this particular subgenre gaining popularity towards the end of that decade. Later, bands such as Rancid added metal influences to the mix, and Ska-Punk found an audience with kids who otherwise listen more to nu-metal than ska.