No rock progressivo, épico é uma composição longa, normalmente acima de 20 minutos, em alguns casos chegando até a uma hora, que compõem a forma mais pura e distinta do gênero. A maioria dos épicos varia entre 15 e 25 minutos.
Normalmente os épicos são divididos em partes distintas em tempo, escala, instrumentos e sonoridade, porém coesas em estilo. Um exemplo é a clássica Close To The Edge (1972), da banda inglesa Yes, que é dividida em 4 partes, cada uma composta por membros diferentes da banda. O modo como a música é conduzida e como suas partes são balanceadas tornaram-se uma referência no gênero. Algumas vezes, determinadas partes de um épico são lançadas separadamente como um single, como foram Gates of Delirium do Yes (de onde se tirou o single Soon), ou Supper's ready do Genesis (de onde se tirou o single Willow Farm).
Um épico é a recorrência mais clara do rock progressivo à música clássica, de onde ele teve suas origens. Mesmo assim, os épicos atuais seguem as tendências e estilos de cada banda. Green Carnation, por exemplo, no seu épico Light of Day, Day of Darkness, toca uma hora de metal. Rush, no épico 2112 (20:37), utiliza-se bastante de seu estilo próprio, também pesado.
Os épicos às vezes são divididos em duas ou mais faixas de um CD, como faz Pendragon (Queen of hearts, Not of this world), mas são assim consideradas porque trata-se de uma única composição. Jethro Tull, por exemplo, criou dois épicos com mais de 40 minutos cada utilizando os dois lados do LP, que não suportava muito mais que 20 minutos por lado. Nessa época, a maioria dos épicos ocupava um lado inteiro do disco.
Álbuns conceptuais Outra forma pura de rock progressivo são os álbuns conceptuais. Eles são quase o oposto de um épico: em vez de uma música longa, o álbum é composto por diversas músicas, normalmente menores, porém com o mesmo tema. Freqüentemente, essas músicas são conectadas, formando uma única composição, como o álbum de Marillion em 1985, Misplaced childhood. Não é totalmente aceito que músicas como essa sejam consideras épicos.
Épicos por década Aqui são listados alguns exemplos de épicos no rock progressivo ou metal progressivo, por década de lançamento.
Década de 60 Ano Artista Álbum Música Duração 1967 Pink Floyd Tonite let's all make love in London (EP) Interestellar overdrive 16:46 1968 Iron Butterfly In-A-Gadda-Da-Vida In-A-Gadda-Da-Vida 17:05 1968 Procol Harum Shine on brightly In held 'twas in I Glimpses of Nirvana 'Twas tea time at the circus The Autumn of my madness Look to your soul Grand finale 17:39 1968 The Jimi Hendrix Experience Electric Ladyland 1983… (A Merman I Should Turn to Be) 13:39 1969 Golden Earring Eight Miles High Eight Miles High 19:00
Década de 70 Ano Artista Álbum Música Duração 1970 Pink Floyd Atom Heart Mother Atom Heart Mother Father's shout Breat milky Mother fore Funky dung Mind your throats please Remergence 23:45 1970 King Crimson Lizard Lizard Prince Rupert awakes Bolero: The peacock's tale The battle of the glass tears 23:151971 Caravan In The Land Of Grey And Pink Nine Feet Underground Nigel Blows a Tune Love's a Friend Make It 76 Dance of the Seven Paper Hankies Hold Grandad by the Nose Honest I Did! Disassociation 100% Proof" 22:43 1971 Focus Moving Waves Eruption Orfeus Answer Orfeus Answer Pupilla Tommy Pupilla Answer The Bridge Break Euridice Dayglow Endless Road Answer Orfeus Euridice 23:04 1971 Pink Floyd Meddle Echoes 23:28 1971 Van der Graaf Generator Pawn Hearts A plague of lighthouse keepers Eyewitness Pictures/Lighthouse Eyewitness S.H.M. Presence of the night Kosmos tours (Custard's) Last stand The clot thickens Land's end We go now 23:04 1971 Emerson, Lake & Palmer Tarkus Tarkus Eruption Stones Of Years Iconoclast Mass Manticore Battlefield Aquatarkus 20:41 1972 Jethro Tull Thick as a brick Thick as a brick 43:36 1972 Focus Focus III Answers? Questions! Questions? Answers! 19:54 1972 Focus Focus III Anonymus II Anonymus II (Part 1) Anonymus II (Conclusion) 26:21 1972 Genesis Foxtrot Supper's ready Lover's leap The guaranteed eternal sanctuary man Ikhnaton and Itsacon and their band of merry men How Dare I be so Beautiful Willow farm Apocalypse in 9/8 (featuring the delicious talents of Gabble Ratchet) As sure as eggs is eggs (aching men's feet) 22:54 1972 Yes Close to the edge Close to the edge The solid time of change Total mass retain I get up, I get down Seasons of man 18:44 1972 Banco del Mutuo Soccorso Banco del Mutuo Soccorso Il giardino del mago Passo dopo passo Chi ride e chi geme Coi capelli sciolti al vento Compenetrazione 18:26 1973 Jethro Tull A Passion Play A Passion Play 44:58 1973 Emerson, Lake & Palmer Brain Salad Surgery Karn Evil 9 First Impression, part 1 First Impression, part 2 Second Impression Third Impression 29:40 1973 Yes Tales From Topographic Oceans Ritual: Nous Sommes du Soleil 21:33 1973 Yes Tales From Topographic Oceans The Revealing Science of God: Dance of the Dawn 20:20 1973 Yes Tales From Topographic Oceans The Remembering: High the Memory 20:36 1973 Yes Tales From Topographic Oceans "The Ancient": Giants Under the Sun 18:37 1973 Triumvirat Illusions on a double dimple Illusions on a double dimple Flashback Schooldays Triangle Illusions Dimplicity Last dance 22:55 1973 Triumvirat Illusions on a double dimple Mister ten percent Maze Dawning Bad deal Roundabout Lucky girl Million dollars 21:12 1974 Yes Relayer The Gates of Delirium 21:54 1974 Camel Mirage Lady Fantasy Encounter Smiles For You Lady Fantasy 12:45 1974 Focus Hamburguer Concerto Hamburger Concerto Starter Rare Medium I Medium II Well Done One for the Road 20:19 1975 Rush Caress of Steel The fountain of Lamneth In the valley Dialects and narpets No one at the bridge Panacea Bacchus plateau The fountain 19:59 1975 Renaissance Scheherezade and other stories Song of Scheherezade 24:39 1976 Rush 2112 2112 Overture Temples of the Syrinx Discovery Presentation Oracle: the dream Soliloquy The grand finale 20:37 1977 Pink Floyd Animals Dogs 17:08 1977 Yes Going for the one Awaken 15:35 1978 Emerson, Lake & Palmer Love beach Memoirs of an officer and a gentleman Prologue / The Education Of A Gentleman Love At First Sight Letters From The Front Honourable Company (A March) 20:16 1978 Rush Hemispheres Cygnus X-1 Book II: Hemispheres Prelude Apollo (Bringer of Wisdom) Dionysus (Bringer of Love) Armageddon (The Battle of Heart and Mind) Cygnus (Bringer of Balance) The Sphere (A Kind of Dream) 18:081979Anyone's DaughterAdonisAdonis Come Away The Disguise Adonis The Epitaph24:13
Década de 80 Ano Artista Álbum Música Duração 1982 Marillion Market Square Heroes (EP) Grendel Heorot's Plea and Grendel's Awakening Grendel's Journey Lurker At The Threshold Finale 17:15 1983 Genesis Genesis Home By The Sea Second Home By The Sea 11:14 1983 IQ Tales From The Lush Attic The Last Human Gateway 19:58 1983 IQ Tales From The Lush Attic The Enemy Smacks 15:56 1983 Mercyful Fate Melissa "Satan's Fall" 11:23 1984 Iron Maiden Powerslave "Rime of the Ancient Mariner" 13:35 1984 Venom At War with Satan "At War with Satan" 19:57 1986 Genesis Invisible Touch Domino In The Glow Of The Night The Last Domino 10:45 1987 Helloween Keeper of the Seven Keys Part 2 Helloween 13:18 1988 Helloween Keeper of the Seven Keys Part 2 Keeper of the Seven Keys 13:37 1988 Talk Talk Spirit of Eden The Rainbow The Rainbow Eden Desire 22:38
Década de 90 Ano Artista Álbum Música Duração 1991 Pendragon The world Queen of hearts Queen of hearts ...A man could die out here... The last waltz 21:53 1992 Echolyn Suffocating the Bloom A suite for the everyman Only Twelve A Cautious Reponse Bearing Down Cash Flow Shuffle Mr. Oxy Moron Twelve's Enough I Am the Tide Cannoning in B Major Picture Perfect Those That Want to Buy Suffocating the Bloom 28:13 1992 Änglagård Hybris Gånglåt från Knapptibble 19:36 1992 Manowar The Triumph of Steel Achilles, Agony and Ecstasy in Eight Parts Prelude I. Hector Storms the Wall II. The Death of Patroclus III. Funeral March IV. Armor of the Gods V. Hector's Final Hour VI. Death Hector's Reward VII. The Desecration of Hector's Body A. Part 1 B. Part 2 VIII. The Glory of Achilles" 28:38 1993 Pendragon The Window of Life The last man on Earth 14:46 1993 Disembowelment Transcendence into the Peripheral A Burial at Ornans 14:38 1994 Galleon Heritage and Visions Permanent vacation 16:26 1994 Dream Theater Awake A Mind Beside Itself Erotomania Voices The Silent Man 20:24 1995 Dream Theater A Change of Seasons A Change of Seasons The Crimson Sunrise Innocence Carpe Diem The Darkest of Winters Another World The Inevitable Summer The Crimson Sunset 23:06 1995 Spock's Beard The Light The water Introduction/The water When it all goes to hell A thief in the night FU/I'm sorry The water (revisited) Runnin' the race Reach for the sky 23:05 1995 Spock's Beard The Light The light The dream One man Garden people Looking straight into the light The man in the mountain Señor Valasco's mystic voodoo love dance The return of the horrible catfish man The dream 15:33 1996 Yes Keys to Ascension That, that is Togetherness Crossfire The giving things That is All in all How did heaven begin Agree to agree 19:15 1996 Opeth Morningrise Black Rose Immortal 20:14 1997 The Flower Kings Stardust We Are Stardust We Are 25:03 1997 Symphony X The Divine Wings of Tragedy The Divine Wings of Tragedy 20:41 1997 Enslaved Eld 793 (Slaget om Lindisfarne) 16:10 1997 IQ Subterranea The narrow margin 20:00 1998 The Flower Kings Flower Power Garden of Dreams Dawn Simple Song Business Vamp All you Can Save Attack Of The Monster Briefcase Mr Hope Goes To Wall Street Did I Tell You Garden Of Dreams Don't Let The d'Evil In Love is the Word There's No Such Night The Mean Machine Dungeon Of The Deep Indian Summer Sunny Lane Gardens Revisited Shadowland The Final Deal 59:24 1998 Yes Keys to Ascension II Mind drive 18:38 1998 Galleon Mind over matter The wanderer 21:14 1998 Mercyful Fate Dead Again Dead Again 13:41 1999 Neal Morse Neal Morse A whole nother trip Bomb that can't explode Mr. upside down The man who would be king It's alright 23:58
Década de 2000 Ano Artista Álbum Música Duração 2000 Transatlantic SMTPe All of the above Full moon rising October winds Camouflaged in blue Half alive Undying love Full moon rising (reprise) 30:59 2000 Spock's Beard V The great nothing From nowhere One note Come up breathing Submerged Missed your calling The great nothing 27:03 2001 Green Carnation Light of day, day of darkness Light of day, day of darkness 60:06 2001 Transatlantic Bridge Across Forever Duel with the devil Motherless children Walk away Silence of the night You're not alone Almost home 26:43 2001 Transatlantic Bridge Across Forever Stranger in your soul Sleeping wide awake Hanging in the balance Lost and found pt. 2 Awakening the stranger Slide Stranger in your soul 26:23 2001 Magenta Revolutions Man the machine Man and machine War Rememberance The watchers Lightspeed First contact 24:41 2001 Magenta Revolutions Genetesis The new age Renewed purpose A new life The search for faith The creed 22:07 2001 Magenta Revolutions The white witch Overture The white witch The plague Reflection The spell 20:57 2001 Magenta Revolutions Children of the sun Spirit of the land The journey The battle Thanksgiving 19:18 2001 Pendragon Not of this world Not of this world Not of this world Give it to me Green eyed angel 16:26 2002 Echolyn Mei Mei 49:33 2002 Dream Theater Six Degrees of Inner Turbulence Six Degrees of Inner Turbulence Overture About to Crash War Inside My Head The Test That Stumped Them All Goodnight Kiss Solitary Shell About to Crash (Reprise) Losing Time / Grand Finale 42:02 2002 The Flower Kings Unfold The Future The truth will set you free 31:03 2002 The Flower Kings Unfold The Future Devil's playground 24:45 2002 Symphony X The Odyssey The Odyssey Odysseus Theme / Overture Journey To Ithaca The Eye Circe (Daughter Of The Sun) Sirens