Aooom channels doom metal from Saint Petersburg since 2020. Their drawn-out name — extending the mystic syllable 'om' — captures the meditative, infinitely sustained quality of their glacial compositions.

Aorlhac channels epic, medieval Occitan black metal from the Auvergne towns of Aurillac, Clermont-Ferrand, and Saint-Flour, drawing from local folklore and history with hurdy-gurdy woven into their acoustic-only instrumentation. Signed to Les Acteurs de l'Ombre Productions, their albums explore the Occitan heritage of south-central France through some of the most distinctive black metal the country has produced.

Aornos takes its name from the ancient fortress besieged by Alexander the Great and has besieged Miskolc's metal scene with black metal since 2015. Their sound reflects the darkness and severity that the Bükk Mountains surrounding their hometown inspire.

Aorta is a thrash metal and grindcore band from Schwerin, Germany, formed in 2013, combining thrash's speed and precision with grindcore's blast-beat fury from the capital of Mecklenburg-Vorpommern. The band represents the extreme metal underground in northeastern Germany.

Aortic Rupture delivers death metal from Groningen as of 2025. Their cardiovascular-catastrophe name promises the sudden, fatal violence of their debut material from the university city of the northern Netherlands.

Aoryst is a thrash metal band from Osnabruck, Germany, formed in 2024, carrying on the proud tradition of German thrash metal as one of the newest entrants into the scene. The band delivers the genre's characteristic speed and aggression from the Lower Saxony region.

Aoviccan blends folk metal's storytelling with thrash metal's ferocity from Madrid, weaving traditional elements into extreme metal since 2021. Their hybrid approach creates an unusual sonic tapestry that draws from both Spanish folk traditions and modern thrash aggression.

Aovum channels black metal from Helsinki since 2018, adding another distinctive voice to the Finnish capital's inexhaustible black metal community. Their embryonic name suggests a project focused on origins and genesis within darkness.

AoX fuses black and death metal from the Finnish underground since 2014, operating at the volatile intersection of extreme metal's two most aggressive subgenres. Their minimalist name matches the stripped-down intensity of their dual-genre assault.