Metal music generally is a very fast, aggressive, loud and technical sounding music, ofcourse it depends on what type is i mentioned erlier, there are so many different types. After Black Sabbath, metal bands started growing and progressing but still keeping the same raw sound.
From the 1980's up to today metal has evolved into so many different forms such as Black metal, Death metal, Groove metal, Progressive metal, Power metal, Gothic metal, Funk metal, Folk metal, Rap metal, Punk metal, Experimental, Stoner metal, Drone metal, Sludge Metal, Industrial metal, Extreme metal and hundreds of different combinations of the above.
Warning, watch out for fake metal or poser metal bands or emo bands such as Bring me the Horison, Suicide Silence, Black Veil Brides, Slipknot, to name a few.
(Metal head): Fucking lol.
(Emo kid): WHAT? UR U SERIOUS ???? Metal Music IS GAY!!
(Metal head): then simply puts some Strapping young lad on full volume, emo kid's then explodes into a wonderfull rainfall of blood an guts witch lands on the ground spelling out the letters METAL IS FUCKING AWESOME !!!!