Progressive rock (shortened to prog, or prog rock when differentiating from other "progressive" genres) is an ambitious, eclectic, and often grandiose style of rock music which arose in the late 1960s, reached the peak of its popularity in the early 1970s, and continues as a musical form to this day. Progressive rock began in England and remained largely a European movement, although there are a few notable American and Canadian progressive rock bands. This music style draws many influences from classical music and jazz fusion, in contrast to American rock, which was more influenced by rhythm & blues and country. Over the years various sub-genres of progressive rock have emerged, such as symphonic rock, art rock, math rock and progressive metal.