Music

The music in The Binding of Isaac: Rebirth, The Binding of Isaac: Afterbirth, The Binding of Isaac: Afterbirth † and The Binding of Isaac: Repentance was created by Ridiculon. The full albums for each consist of 32, 9, 4 and 31 tracks, respectively. However, Jesus Loves Uke, He’s the Number One, and Descensum are exclusive to the Rebirth album and thus not heard in-game, though Jesus Loves Uke can be seen unused in the resources. That being said, the Rebirth album doesn’t include the tracks for the intro and epilogue, adding back up to 31 in-game tracks. Afterbirth replaces Genesis with its own rendition titled Regenesis, resulting in a net gain of 8 tracks for a total of 39 tracks in Afterbirth. Afterbirth+ also has the Ante Lucem bonus track that cannot be heard in-game, so with a gain of 3 tracks there is a total of 42 tracks in Afterbirth+ that can be heard in-game. The Rebirth soundtrack can be purchased through Steam, however the Afterbirth, Afterbirth † and Repentance soundtracks cannot. All three soundtracks are purchasable from Ridiculon's Bandcamp page.

Nearly every main floor track gains instruments when enough smaller enemies or bosses are in the room. The variant can be heard in the soundtrack version in the second loop of the song. What instruments gained are indicated in bold next to the tracks.

Songs with "quotation marks" next to their name are not part of the track title, but are approximate translations from Latin to English.

The Binding of Isaac: Rebirth

 * Genesis 22:10 (Title)
 * Diptera Sonata (Basement) [Guitar]
 * Crusade (Basic Boss Fight)
 * Sodden Hollow (Caves) [Bass Guitar]
 * The Forgotten (Secret Room)
 * Abyss (The Depths) [Ambient Sounds]
 * Matricide (Vs. Mom)
 * The Calm (Boss Defeated)
 * Viscera (The Womb) [Drums]
 * Ventricide (Vs. Mom's Heart/It Lives)
 * Acceptance (Game Over)
 * Anima Vendit "Life Merchant" (Devil Room)
 * Duress (Sheol) [Drums]
 * Hericide (Vs. Satan)
 * Murmur of the Harvestman (Store)
 * Empty Vessels (Angel Room)
 * Everlasting Hymn (Cathedral) [No Change]
 * Infanticide (Vs. Isaac)
 * Ambush (Mini-Boss and Challenge Room Battle)
 * Tome of Knowledge (Library)
 * Periculum "Risks" (The Cellar) [Guitar]
 * Capiticus Calvaria (Catacombs) [Guitar]
 * When Blood Dries (Necropolis) [Guitar]
 * Sketches of Pain (The Chest) [Guitar]
 * Ascension (Vs. ???)
 * Devoid (Dark Room) [Ambient Sounds]
 * The Fallen Angel (Vs. The Lamb)
 * Tribute (Credits)
 * Genesis 13:37 (Arcade)
 * Hush (Jesus Loves Uke) (BONUS)
 * Descensum "Descent" (BONUS)
 * He's the Number One (BONUS)

The Binding of Isaac: Afterbirth

 * ReGenesis (Updated Title Theme)
 * Cerebrum Dispersio "Brain Dispersion" (Boss Fight - Alternate)
 * Cicatrix "Scar" (Scarred Womb) [Drums]
 * Fundamentum "Foundation" (Burning Basement) [Guitar]
 * Kave Diluvii "Cave Flood" (Flooded Caves) [Guitar]
 * Nativitate "Birth" (Blue Womb)
 * Morituros "Dying Man" (Vs. Hush)
 * Pulso Profundum "Deep Pulse" (Dank Depths) [Drums]
 * Chorus Mortis "Dance of Death" (Vs. Ultra Greed)

The Binding of Isaac: Afterbirth+

 * Terminus (The Void) [Guitar]
 * Delirium (Vs. Delirium)
 * Sepulcrum "The Tomb" (Ending 20)
 * Ante Lucem "Before the Light" (BONUS)

The Binding of Isaac: Repentance

 * Genesis Retake Light (Updated Title Theme)
 * River Of Despair (Downpour) [Guitar]
 * Juggernaut (Boss Fight - Alternate)
 * Fissure (Mines) [Guitar]
 * Super Secret Room
 * Walls Of Denial (Mausoleum) [Guitar]
 * Dread (The Calm Twisted)
 * Carrion (Corpse) [Guitar/Base Guitar]
 * Morticide (Vs. Mother) [Guitar]
 * Caesarian (Utero) [Drums]
 * Armageddon (Boss Rush)
 * StarGazer (Planetarium)
 * Night Soil (Dross) [Guitar/Synths]
 * Absentia "Absence" (Ashpit) [Guitar]
 * Morning Star (Gehenna) [Guitar]
 * Bygone (Ultra Secret Room)
 * Home
 * Living In The Light (Vs. Dogma)
 * Revelations 13-1 (Vs. The Beast)
 * Genesis Retake Dark (Updated Title Theme - Tainted Character Selection)

Title Meanings
Many titles of music tracks have meanings that hint to the story of the game, as well as some tracks describing the area the track plays in:


 * Genesis 22:10 (Title) - A passage in the Bible which portrays the story of Isaac, describing how Abraham wielded a knife to slaughter his own son, similar to what Isaac's Mom tried to do.
 * Diptera Sonata (Basement) - Diptera is the order for the family of flies, which the caverns is full of, and sonata is a type of song, therefore the track literally meaning "Fly Song".
 * Sodden Hollow (Caves) - Sodden means "saturated with liquid", similar to what caves are sometimes like.
 * Matricide (Vs. Mom) - Matricide means the murder of one's own mother.
 * Viscera (The Womb) - Viscera is the internal organs in the main cavity of the body.
 * Ventricide (Vs. Mom's Heart/It Lives) - A made up word by Edmund McMillen meaning "Killing of the heart".
 * Duress (Sheol) - Duress means intimidation and coercion, which one may think when entering Sheol for the first time.
 * Hericide (Vs. Satan) - Hericide is the act of mudering one's own teacher or master.
 * Empty Vessels (Angel Room) - Possibly referencing that Isaac does not believe that Angels will save him, as they are "empty".
 * Infanticide (Vs. Isaac) - Infanticide is the killing of infants, which Isaac is one of.
 * Capiticus Calveria (Catacombs) - Calveria translates from Latin to "Skull", which the Catacombs is full of, while Capaticus could be seen as Latin gibberish or being derived from Caput, meaning "Head" or Capiticulum, meaning "Chapter".
 * Ascension (Vs. ???) - Referencing that the death of ??? practically means the death of Isaac, and now he is free to ascend to heaven.
 * Devoid (Dark Room) - Referencing that the Dark Room is devoid of any salvation or God.
 * The Fallen Angel (Vs. The Lamb) - Referencing that the Devil was once an angel, who rebelled against God and was sent to Hell to torture sinners.
 * Genesis 13:37 (Arcade) - Not an actual passage in the Bible, but a reference to the gaming term "Leet", which can be spelled with the numbers "1337"
 * Morituros "Dying Man" (Vs. Hush) - Referencing that Hush is the representation of imminent death.
 * Chorus Mortis "Dance of Death" (Vs. Ultra Greed) - Possible reference to some of Ultra Greed's attack moves, such as jumping and spinning in a circle, like a dance.
 * Another translation is "Chorus of Deads", referencing that Greed Mode is full of dead shopkeepers.
 * Terminus (The Void) - A terminus is seen as the "final point in space and time", referencing how The Void is Isaac's final stages of his life.
 * Delirium (Vs. Delirium) - Named after the boss itself
 * Juggernaut (Boss Battle - Alternate) - A juggernaut is a huge, powerful, and overwhelming force or institution.
 * Fissure (Mines) - A fissure is a narrow opening, usually in rock, a possible reference to how you access the Mines, with Isaac placing bomb to open a crack in a Boss Room.
 * Carrion (Corpse) - Carrion is the decaying meat of animals.
 * Morticide (Vs. Mother) - Possibly a made up word or an undiscovered Latin word, but is a combination of the Latin Mort meaning "dead" and Cide meaning "Kill", a reference to how Isaac is killing something in an already dead environment (The Corpse).
 * Caesarian (Utero) - A caesarian is someone who has be effected by a caesarean section.
 * Bygone (Ultra Secret Room) - Bygone means "belonging to an earlier time," meaning that Ultra Secret Rooms may be ancient.
 * Living In The Light (Vs. Dogma) - Taken from a quote in the Bible, talking about the fact that "God is light".
 * Revelations 13-1 (Vs. The Beast) - A passage from the Bible talking about a "Beast with 10 horns and seven heads rising out of the sea", a direct comparison to The Beast boss.

Trivia

 * 3 additional albums were released by Ridiculon. While these specific tracks do not appear in the game, the music consists of content related to the game.
 * The Binding of Christmas
 * The Binding of Isaac: Lullabies
 * The Binding of Isaac: Mutations
 * The title screen theme of The Legend of Bum-Bo is a remix of the Binding of Isaac: Rebirth title theme with the same name.
 * In an interview on Steam by Tyrone Rodriguez of Ridiculon producers Matthias Bossi and Jon Evans, Jon mentioned that every track made for Repentance is his favorite. However, he pointed out three OSTs in particular as what he's most proud of: "'Sodden Hollow' for its dripping groove," "'Sheol' for even being allowed to be so terrifying in a game OST," and "'Delirium' for its dank heaviness."
 * The Boss Rush Theme Armageddon seems to be a remix of the songs "Cerebrum Dispersio" and "Crusade", the standard boss battle themes, with many unique elements mixed in.
 * The Mother fight theme Morticide is the only boss theme that has a second loop similar to a floor’s theme. In game, the first loop is not used. Instead it uses the second loop of the song.
 * The Blue Womb's theme features a combat layer in the OST and the game files, however this is unused due to the floor having no enemies aside from the boss.
 * With the Red Key, it is possible to generate red rooms and the combat layer can be heard in them.
 * It can also be heard in DELETE THIS if the random track selected is this theme.
 * It can also be heard when going through a Crawl Space if it has enough enemies within.