Alternative rock has its roots in the early '80s with bands from all over the world like R.E.M., U2, Pixies, Smiths, Sonic Youth and countless others. In the early '90s the genre expanded further, being the father of the grunge scene (Nirvana, Pearl Jam, Stone Temple Pilots) but also providing other leader bands like Smashing Pumpkins.
Alternative metal is a term used by late '80s (Soundgarden, Alice in Chains) bands mostly originating from the grunge area: Seattle. These bands made alternative rock heavier by adding heavy metal riffs to it. Other classics of the genre are Warrior Soul and the complex Tool who also have progressive leanings to their music.
