Progressive metal
Progressive metal is a fusion between progressive rock and heavy metal. It is one of heavy metal's more complex genres, due to its use of unusual and dynamic time signatures, long compositions, complex compositional structures, and skilled instrumental playing, where instrumental solos are detailed and extended. However, the latest age of progressive metal has favored rougher lyrics and lower-pitched riff sequences with high amounts of strumming. Vocals, if present, are melodic (though there are a few that use unclean vocals), and lyrics are often philosophical, spiritual, or political. Many bands of the genre were influenced by the progressive rock bands Rush and King Crimson, who would often incorporate elements of heavy metal into their music. Examples of the genre include Queensrÿche, Dream Theater, Opeth, Tool, Fates Warning, Mastodon, Gojira and Pain of Salvation.