At the end of 2004 they started to produce their own music, at the beginning much in the dark rock mood ( sound like Joy Division, Cure, Sisters of Mercy ) later they developed a personal style, keeping anyway a strong new-wave and post-punk influence .

http 404 pay great attention to the lyrics, written by Monica, which deal mostly about ordinary fears and nightmares and are often inspired by literary works.

Lyrics are mostly in English, but after a period of time spent working in France, Monica started writing in French and all the new songs since 2016 are in that language