An Oath Enshrined by Honour and Death

Ages of Blood · An Oath Enshrined by Honour and Death (2023)

An Oath in Silence

Raventhrone · Endless Conflict Theorem (2002)

An Oath of Blood and Fire

Lucifuge · Hexensabbat (2024)

An Oath of Devotion

Embryonic Slumber · In Worship Our Blood Is Buried (2021)

An Oath of Retribution

Rutah · Welcome to the End of Days (2007)

An Oath Sworn for the Holocaust

Sargeist · Sargeist / Funeral Elegy (2004)

An Oath Sworn in Bjorgvin

Hades Almighty · ...Again Shall Be (1994)

An Oath Sworn in Sorrow

Sojourner · The Shadowed Road (2018)

An Oath Sworn on the Ashlar Stone

The Lamp of Thoth · This Is Not a Laughing Matter (2017)

An Oath Sworn on the Ashlar Stone

The Lamp of Thoth · No Laughing Matter (2012)

An Oath Sworn on the Ashlar Stone (live)

The Lamp of Thoth · Sing As You Slay (2009)

An Oath to the Void

Astral Path · An Oath to the Void (2016)

An Oath Writ in Blood

Aldheorte · Where Gods Have Eyes to See (2024)

An Obelisk of the World

Hellspawn · The Great Red Dragon (2012)

An Obestian Tale

Dream of Omni · Hardcore Spectrum Disorder (2017)

An Obestian Tale Revisited

Dream of Omni · Hatansion (2022)

A Noble Rot

Human Waste · Misery Obsessions (2026)

A Nobler Rot

Spectral Wound · Terra Nullius (2015)

A noble truth

Asunto · Cuando las sutilezas mueren (2004)

An Obscure Pain

Coffins · Craving to Eternal Slumber (2015)

An Obseding End

Resurrected · Endless Sea of Loss (2006)

An Observation

Cathedral · The Last Spire (2013)

An Obsession Supreme

Shock Narcotic · I Have Seen the Future and It Doesn't Work (2019)

An Obsidian Perception

Unfathomable Ruination · Enraged & Unbound (2019)

An Obsolete Creation

Bizarre · Invocation Codex (2021)

An Obvious Antidote

Dyssidia · Costly Signals (2020)

A Noc Bude Mať Nadvládu

Aeon Winds · And Night Shall Have Dominion (2014)

An Occult Gift Responds

The Chasm · The Scars of a Lost Reflective Shadow (2022)

An Occult Mosaic

Conjureth · Majestic Dissolve (2021)

An Ocean

Ada Rook · 2,020 Knives (2020)

An Ocean Apart

Skycamefalling · 10.21 (2000)

An Ocean Between

Orion, The Fallen · The Druid & The Herbalist (2021)

An Ocean Between Us

As I Lay Dying · An Ocean Between Us (2007)

An Ocean Between Us

Rainover · Transcending the Blue and Drifting Into Rebirth (2013)

An Ocean Between Us - Part I - Chapter Twelve

Crusade of Bards · Tales of Bards & Beasts (2019)

An Ocean Between Us Part III - A New World

Crusade of Bards · Tales of the Seven Seas (2022)

An Ocean Between Us - Part II - Ulysses' Cry

Crusade of Bards · Tales of Bards & Beasts (2019)

An Ocean Between Us Part IV

Crusade of Bards · Tales of Distant Worlds (2026)

An Ocean For The Eyeless

Shoot the Girl First · Follow The Clouds (2013)

An Ocean of Blood

Strigoi · Viscera (2022)

An Ocean of Fire

The Foundation · To Those We've Bid Farewell (2020)

An Ocean of Ire

Unreqvited · Disquiet (2016)

An Ocean of Light

Alder · Sun Worshipper (2016)

An Ocean of Pride

Before the Torn · Burying Saints (2009)

An Ocean of Strange Islands

Nightwish · Yesterwynde (2024)

An Ocean of Strange Islands (orchestral version)

Nightwish · Yesterwynde (2024)

An Ocean of Time

Faithful Darkness · Archgod (2014)

An Ocean of War

Norma Jean · Polar Similar (2016)

An Ocean of Wisdom

Gorguts · Colored Sands (2013)

An Ocean Ov Putrid, Stinky, Vile, Disgusting Hell

Plasmodulated · An Ocean ov Putrid, Stinky, Vile, Disgusting Hell (2025)