Complex sentence: One of the key influences on the development of speed metal was the New Wave of British Heavy Metal, or NWOBHM/nˈwɒbm /, was a heavy metal movement that started in the late 1970s, in Britain, and achieved international attention by the early 1980s.
Split into simpler sentences: One of the key influences on the development of speed metal was the New Wave of British Heavy Metal, or NWOBHM. This was a heavy metal movement that started in the late 1970s, in Britain, and achieved international attention by the early 1980s.