Aridonia formed in San Salvador de Jujuy in Argentina's extreme northwest, with a lineup of Fernando Echenique on guitar and vocals, Benjamin Yecora on guitar, Tomas Longombardo on bass, and Matias Paiva on drums. The band released their debut EP, "EP1", in 2017, followed by their self-titled full-length in 2020, a seven-track record praised for bridging stoner metal, doom, and progressive rock influences. Comparisons to Tool, Kyuss, and Baroness have been noted by reviewers, reflecting the band's blend of heavy riffing and atmospheric song structures.

Ariel/Kaliban is a power and folk metal band from Palmeira dos Índios, Alagoas, Brazil, founded in 2007 and drawing heavily on Brazilian literature for their Portuguese-language lyrics. Their 2012 EP O Trágico marked a darker turn in their sound, blending power metal structures with flute and folk elements while remaining rooted in literary themes of mortality and the ephemeral. The five-piece lineup features flute alongside guitars and bass, giving their music an uncommon texture within the northeastern Brazilian metal underground.

Arithmetic Overflow is an instrumental progressive post-metal band from João Pessoa, Paraíba, Brazil, formed around 2019 and operating in a corner of the Brazilian metal scene rarely occupied by acts from the northeast. Their sound fuses djent-influenced rhythmic precision with expansive post-metal atmospherics, as heard on their 2020 album Expanding the Mind. The band records and releases independently, with their music available via Bandcamp.

Arjé is a power metal project from Perico, Jujuy, Argentina, led by multi-instrumentalist David Aguirre. The band's foundational album "Buscando Horizontes" became a touchstone of the Latin American Christian heavy metal underground, later reissued in remastered form through Headlight Productions with bonus tracks.

Arkanus is a Brazilian heavy metal band formed in 1994 and active since the mid-1990s underground scene. The band built their catalog through a series of self-released demos including Black Out (1999), Six Feet Under (2000), and Mysterious Places (2002), demonstrating a long commitment to independent heavy metal in Brazil. Despite years of activity, they have remained a consistently underground act without major label backing.

Arkhaikus was a thrash metal band from Presidente Prudente, São Paulo, Brazil, active from 2010 until their split-up and operating under several earlier names including Slackerness and Metaldier before settling on the final moniker. The band's lyrical themes centered on warfare, evil, and metal culture, fitting squarely within the aggressive thrash tradition of the Brazilian interior. They documented their live activity with a bootleg recording from a 2011 show in Santo Anastácio.

Arkhôn Tôn Daimoniôn is a black metal band from Salvador, Bahia, Brazil, founded in 1995 by vocalist Duxgor and guitarist Grim Abra-Melim Offilatrus, making them one of the longer-running underground black metal acts out of Brazil's northeast. Rooted in explicitly Satanic and blasphemous themes, they released the demo Sacrum Ex Operam Dare in 1998 and Visions of the Apocalypse in 1999, both circulated in the tape-trading underground. The band debuted live at the Occult Ritual of Fire Festival in December 1996 and has continued performing into the 2020s.

Armoured Knight is a heavy/speed metal band from Peñaflor, Chile, active since 2012, whose lineup has centered on guitarist Cristian León alongside vocalist José Tapia and bassist Christopher Falk. They built their catalog across three EPs — "Prophecy of Tomorrow" (2013), "Ashes of Glory" (2017), and "The Sacred Flame" (2020) — before releasing their debut full-length "The Quest for the Sacred Melody" in October 2025 through German label Dying Victims Productions.

Aroma de Saturno is a doom, sludge, and stoner metal band from Blumenau, Santa Catarina, Brazil, formed in 2018. They occupy the slower, heavier end of the Brazilian metal underground, releasing their self-titled EP and the track Ponto Sem Retorno through Bandcamp. Blumenau's German-immigrant heritage and industrial past give the city an unusual cultural backdrop for the kind of heavy, atmospheric metal Aroma de Saturno pursues.