Types of Insomnia. There are two types of insomnia: primary insomnia and secondary insomnia. 1  Primary insomnia: Primary insomnia means that a person is having sleep problems that are not directly associated with any other health condition or problem.
System of a Down's music has variously been termed alternative metal, nu metal, hard rock, progressive metal, thrash metal, art rock and avant-garde metal.
Synthwave (1980s genre), a new wave/cold wave subgenre from the 1980s. Synthwave (2000s genre), an electronic music subgenre from the 2000s.