Metal music began in the late 60s classified as a genre of rock music, largely performed by bands from the United States and the UK. Blues-rock, psychedelic rock, and acid rock music were the root of metal music. The bands developed thick, loud, and sludgy sounds. And characterized by emphatic beats, extended guitar solos, heavy use of distortion, and loud sounds. The lyrics and performances were aggressive just like the sound of their music.
In the late 60s Led Zeppelin, Deep Purple, and Black Sabbath were founded and are considered to be the pioneers of metal music. These three bands were the first to get the attention of audiences and inspired other bands to play heavy metal music. These bands did not only play music with loud and aggressive sounds, the lyrics they wrote were about the problems that were around and the lyrics contained aggressiveness. The metal bands attracted a huge number of audiences and at the same time, they were derided by critics.
Soon by the end of the late 60s, American bands like Alice Cooper and Kiss came with a raw sound and dark theatrical showcase. As time passed by the 70s bands like Judas Priest and Motörhead came with heavier sound and dark lyrics.
In the late 70s in the UK the new wave of British heavy metal a nationwide musical movement started from where bands like Iron Maiden and Saxon came. These bands were another influential band that got the attention of a huge number of audiences and polished the name of heavy metal. They were and still are an inspiration for most heavy metal bands.
During the 1980s glam metal became popular with bands like Bon Jovi and Motley Crue. These types of metal music were performed with make-ups and flashy clothes. And on the other hand thrash metal came into the mainstream with a more aggressive style, iconic bands like Metallica, Slayer, Megadeth, and Anthrax, are known as the Big Four Band. The big four bands had attained arena-filling status. Thrash metal basically performed songs related to war.
While mainstream metal bands were making records in clean and audible vocal tones in the underground scene metal bands were quite different. Bands like Venom, Mercyful Fate, Celtic Frost, and Bathory forged a template for extreme genres like death metal and black metal, a subcultural phenomenon.
Death metal evolved from thrash metal was a metal movement in the North American and European metal scene. They adopted and emphasized the elements of blasphemy and diabolism. Death metal adapted to speed and aggression from both thrash metal and hardcore rock. They use a variety of vocal techniques involving gutturals, death growls, high-pitched screaming. The guitars are heavily distorted and have extremely fast percussion, often with rapid double bass drumming and blast beats.
At the same time, black metal emerged in Europe. Black metal bands use satanic themes and stand for anti-Christ values. Vocals style used is mostly screeching and growling. Lyrics are mostly against Christian values and wars. Black metal bands from the Scandinavian black metal scene became associated with violence in the early 1990s, with Mayhem and Burzum linked to church burning.
During the 90s, metal branched out into a seemingly endless number of sub-genres. Bands from the underground scene came up with sub-genres like death-grind. It consists of the mixed sound of death metal and grind. Other sub-genres were symphonic metal consisting of symphonic notes on guitar and keyboard, fast double bass drums, and screeching vocals.
In this decade of metal music, the most controversial and questioned style of metal often referred to as nu-metal came into the scene. This style of music consists of hip-hop and rap beats as well. Most of the nu-metal band vocals were performed in a hip-hop rap verse. Hip-hop music is a totally different culture. And metal culture is not fond of mixing music from other genres. So, this is also why this is the most questioned sub-genre of metal.
Another sub-genre that got limelight in both mainstream and the underground scene was groove metal. This genre consists of groovy guitar riffs. The lyrics are about strength and realism. And it includes different sets of vocal styles: clean, growling and some even had high pitched vocals.