Proto-punk (or protopunk) is rock music from the 1960s to mid-1970s that foreshadowed the punk rock movement. A retrospective label, the musicians involved were generally not originally associated with each other and came from a variety of backgrounds and styles; together, they anticipated many of punk's musical and thematic attributes. The tendency towards aggressive, simplistic rock songs is a trend critics such as Lester Bangs have traced to as far back as Ritchie Valens' 1958 version of the Mexican folk song "La Bamba", which set in motion a wave of influential garage rock bands including the Kingsmen, the Kinks, the 13th Floor Elevators and the Sonics. By the late 1960s, Detroit bands the Stooges and MC5 had used the influence of these groups to form a distinct prototypical punk sound. In the following years, this sound spread both domestically and internationally, leading to the formation of the New York Dolls and Electric Eels in the United States, Dr. Feelgood in England, and the Saints in Australia.