Nightmare is the title track from Avenged Sevenfold's fifth studio album Nightmare, released in 2010. The American heavy metal band wrote it as a dark, theatrical opener, and the song became one of their most recognisable releases. Its distinctive intro, moving from an eerie melody to full guitars and drums, made it easy to excerpt online. Short clips spread through gaming videos, edits and soundboards, where the build and drop are now reused far beyond the original fanbase as a shorthand for something ominous arriving.