Ayax is a power metal band from Buenos Aires, Argentina whose lineup has included vocalist Nicolas Cabrera, guitarists Gustavo Dhaini and Martin Oviedo, bassist Oscar Pedini, keyboardist Pablo Marciello, and drummer Gustavo Nemitz. The band has been active in the Argentine power metal scene and released an early EP in 2005.

Aygan is a progressive metal band from São Paulo, Brazil, formed around 2001 and active into the 2010s. Their sound blends heavy riffing, groove, and progressive rock complexity, landing somewhere between melodic hard rock and progressive metal. The band released the full-length album "Plastic City" in 2010 — recorded at Mr. Som Studios in São Paulo and premiered live at the Fúria Festival on a bill that included Sepultura and André Matos.

Ayin was a technical death metal band from Campo Grande, Mato Grosso do Sul, Brazil. The project was conceived by guitarist/vocalist Abner Ramires in 2003 and realized as a full band in 2010 with the addition of bassist Tiago Romeo and drummer Leonardo Treuherz. Ayin wove themes of chaos, conspiracy, and Thelema through dense, technically demanding compositions, releasing the album "Ordo ab Chao" on Brutal Records before eventually disbanding.

Ayperos was a black metal band from São Paulo, Brazil, active from 1994 to around 2021. The band took its name from the demonological Prince of Hell said to command thirty-six legions of demons, and their lyrical themes orbited occultism, Satanism, and Luciferian philosophy. They remained an underground independent act throughout their career, releasing material that adhered to classic second-wave black metal aesthetics.

Aypheros is a black metal band from Santiago, Chile, founded by guitarist and vocalist Jorge Pilquian (performing as Haizum), with current members including guitarist Ulthar, guitarist Rhaeadr, bassist H.S., and drummer Kerberos. The band has released three full-lengths — Ascendet Novissima Tua (2014), TziTzaudel (2018), and Impetu Spiritus (2023) on Umbrium Records — alongside the 2019 EP Oboth Iddeonim.

Azael was a black metal band from Pedregulho, São Paulo state, Brazil. Despite forming in 2025 and having an extremely brief lifespan before splitting up, the band operated within the raw black metal tradition common to the Brazilian interior underground scene. Details on their releases remain sparse.

Azator is a Buenos Aires blackened thrash metal band whose lineup has included guitarist and vocalist Facundo Batista alongside guitarist Juan Manuel Arabehety, keyboardist Federico Pozzo, and drummer Santiago Sauza. Their 2019 EP "Horrors From Aeons Past", released on Corpse Torture Records, drew praise for keeping a pure blackened thrash sound anchored by chilling black metal vocals over a driving thrash framework.

Azbuk was a São Paulo band whose sound shifted from black metal in its early years to death metal in later recordings, making them an outlier in Brazil's typically genre-entrenched underground. Founded in 1997, the band had an on-again, off-again existence over two decades with rotating lineups and evolving lyrical themes — from Christian-influenced content to war and social commentary and back again. Their Bandcamp discography includes the "Meremoth" EP among other releases.

Aziagus is a Brazilian black 'n' roll band formed in 2022, blending the primitive drive of black metal with hard rock swagger in the tradition of acts like Motorhead and Darkthrone's later records. The band operates in Brazil's underground extreme metal circuit and has a presence on Metal Archives, though their city of origin is unconfirmed. Their music emphasizes raw energy and groove over technical elaboration.