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.
In the late 80s, âgrungeâ did actually define a sound â high levels of distortion, feedback, fuzz effects, a fusion of punk and metal influences. Though the bands attributed to the label definitely had unique talents, there was definitely a similar âsoundâ there.