Thrash metal generally features fast tempos, low-register, complex guitar riffs, high-register guitar solos and double bass drumming. Thrash metal rhythm guitar parts are often palm-muted to create a tighter and more precise sound. Palm-muted parts are often played with a “crunch” distortion guitar tone. Vocally, thrash metal can employ anything from melodic singing to shouted vocals.
Most thrash guitar solos are played at high speed, as they are usually characterized by shredding, and use techniques such as sweep picking, legato phrasing, alternate picking, tremolo picking, string skipping, and two-hand tapping. Thrash lead guitarists are often influenced by the New Wave of British Heavy Metal movement.
Thrash guitar riffs often use chromatic scales and emphasize the tritone and diminished intervals, instead of using conventional single scale based riffing. For example, the intro riff of Metallica’s “Master of Puppets” (the title track of the namesake album) is a chromatic descent, followed by a chromatic ascent based on the tritone.
Speed, pacing and time-changes also define thrash metal. Thrash tends to have an accelerating feel which may be due in large part to its aggressive drumming style. For example, thrash drummers often use two bass drums, or a double-bass pedal, in order to create a relentless, driving beat.
To keep up with the other instruments, many thrash bassists use a pick. However, some prominent thrash metal bassists have used their fingers, such as Frank Bello, Greg Christian, Steve Di Giorgio, Robert Trujillo and Cliff Burton. Here is a list of 10 best thrash metal bands.
(SOURCE: WIKI – http://en.wikipedia.org/wiki/Thrash_metal)