Dir En Grey has been categorized in many genres such as extreme metal, alternative, experimental, avant-garde and various others. Dir En Grey's format has been subject to change throughout their career, initially being a rather experimental form of alternative rock. Some tracks of their debut album "Gauze" also demonstrated a distinct pop appeal, which was largely dropped in favor of a more progressive sound on the following albums, "Macabre" and "Kisou". While up to that point some songs had already been more fast-paced, raw and aggressive than others, the band's music took a decisive turn with the release of the EP Six Ugly, from then on sporting more metal influences in general. Dir En Grey's style gravitated towards riffs and song structures more along the lines of contemporary North American fusion genres, such as nu metal and metalcore, until 2007's "The Marrow of a Bone". In a review of their sixth full-length album, "The Marrow of a Bone", AllMusic's Thom Jurek comments on their evolution and diversity, saying: