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.
What music genre does Disturbed best fit under? I've heard they came out as nu-metal. Some have labeled them under metal, others as hard rock and alternative metal or alternative rock. I know their third album contains more elements of heavy metal while the other 2 were nu metal / rock.