There are four artists on last.fm with this name:

1. Matanza was a b… Read Full Bio ↴There are four artists on last.fm with this name:

1. Matanza was a band from Rio de Janeiro (Brazil). Their music is a blend of Hardcore Punk, Country and Heavy Metal, thus forming the genre that the media titled Countrycore.

Matanza was conceived in 1996 by Jimmy London and Donida, given the idea to explore the simple and straightforward melodies of the early career of the American singer Johnny Cash, adapted to the tempo of a drum was heard as that of Scottish band The Exploited.

The band has a sarcastic and cynical lyrics that speak of hatred, violence, alcohol and women. They have an atmosphere of old American West. The band members are fans of Johnny Cash, and in 2005 they recorded an album of cover songs to songs of the early stage of his career, dubbed To Hell With Johnny Cash. In 2006 album, A Arte do Insulto, Matanza explores various aspects of traditional Irish music.
The main composers are Donida and Jimmy London.

Members:
Jimmy London (vocals)
Mauricio Nogueira (guitar)
China (bass)
Jonas (drums)

Discography:
Santa Madre Cassino (2002)
Música Para Beber e Brigar (2003)
To Hell With Johnny Cash (2005)
A Arte do Insulto (2006)
MTV Apresenta Matanza - Ao Vivo no Hangar 110 (2008)

Official website:
http://www.matanza.com.br

2. Matanza is a new Anabatic Records band from Chile.

Soundcloud Page:
https://soundcloud.com/matanza

3. Matanza is a mexican Grindcore (or Goregrind, considering their lyrics) band from Mérida, Yucatán.
The band started in 2005, and is still active to this day.
It has lots of demos and splits, but the only actual Full Lenght is called Encontrados Muertos, which was released in 2012 as an independent album.

Discography:

Demo 1 (2006)
Malnacido - Demo (2007)
Cadaveres EP (2007)
Mutilando Cuerpos - Single (2008)
Grind Party At Home - Split (2009)
Encontrados Muertos (2012)
Mexico Vs Russia - Split (2013)
Muertos EP (2015)

Official Site (Blog):
http://matanza-mex.blogspot.com.br/

Official Facebook Page:
https://www.facebook.com/Matanza.mex

Official Bandcamp Page:
https://matanzamex.bandcamp.com/

4. Matanza is a groove metal band from Panamá.

Official Facebook Page:
https://www.facebook.com/mtzmetal

Official Instagram Page:
https://www.instagram.com/matanza_anarkia/