THRASH METAL!!!!!!

Thrash Metal is also known as speed metal, and since many of the early thrash bands were from San Francisco, it became known as Bay Area Thrash. It started in the early to mid '80s and was at its peak in the late '80s. Thrash bands were influenced by New Wave Of British Heavy Metal (NWOBHM) and hardcore punk. Thrash was also the inspiration for later extreme genres such as death and black metal. There was also a strong European thrash scene, especially in Germany where bands such as Kreator, Sodom and Destruction led the way.

Musical Style

Thrash is driven by the guitar. It's played at a furiously fast pace with a staccato, percussive guitar sound. It layers fast riffs with higher pitched solos. Many thrash bands use the double bass drum.

Vocal Style

Thrash vocals are usually very aggressive and sometimes angry sounding, but unlike death or black metal, they are still understandable.

Pioneers :

Metallica

Although there were some artists that incorporated elements of thrash into their music, Metallica's 1983 release Kill 'Em All is generally considered to be one of the first thrash albums. Former member Dave Mustaine wrote some of the songs on that record and went on to form another seminal thrash band, Megadeth. Metallica went on to release several classic thrash albums, and although their style has evolved, they still hold on to their thrash roots.

Slayer

Slayer is a little more extreme than Metallica, and their debut album Show No Mercy was released in 1983. 1986's Reign In Blood is considered by many to be the best thrash album ever recorded. Like Metallica, Slayer has had longevity and continue to show the younger generation how it's done.

Recommended Albums :

Metallica - Master Of Puppets

Slayer - Reign In Blood

Megadeth - Peace Sells...But Who's Buying

Anthrax - Among The Living

Exodus - Bonded By Blood

Nuclear Assault - Handle With Care
Annihilator - Alice In Hell

Stormtroopers of Death (SOD) - Speak English Or Die

Testament - The Legacy

Overkill - Horrorscope

Sepultura - Beneath The Remains

Kreator - Pleasure To Kill

-info from About.com-