Progressive black metal quite naturally combines elements of progressive metal and black metal. The tag covers a wide range of music, as artists like Wolves in the Throne Room tend more towards the black side of the spectrum while artists like Mirrorthrone tend more towards the progressive side, but common elements in nearly all music tagged thus include progressive characteristics such as use of odd time signatures, complex compositional technique, and lengthy songs that incorporate multiple movements; and black metal characteristics such as harsh, often shrieked vocals, tremolo picking, and blast beats. There is quite a bit of overlap with symphonic black metal, avant-garde metal and the less frequently used technical black metal as well.