"Crazy Night" (クレイジーナイト, Kureijī Naito) (also known as "Crazy Nights") is the fourth single by Japanese heavy metal band Loudness, from their 1985 album Thunder in the East. Written by lead vocalist Minoru Niihara and guitarist Akira Takasaki and produced by Max Norman, the single was released by Nippon Columbia on December 1, 1984, in Japan and by Atco Records on November 1, 1985. The song was the band's big break in the American metal scene and has since become their signature song.[2][3][4]
The chant of "M-Z-A!" featured in the song came about when Norman asked Niihara to come up with something to sing over the main riff between the chorus and next verse. "M-Z-A!" means nothing, and it was intended to be replaced with another line in post-production. When Niihara couldn't come up with anything to replace it, the "M-Z-A!" chant survived.
Loudness has re-recorded the song in their self-cover albums RockShocks (2004) and Samsara Flight (2016).[5]