A summary + some additions
Tolkien:
Marillion
Camel (Nimrodel, The Procession, The White Rider)
Bo Hansson
Rick Wakeman
Rush (Rivendell)
Jon Anderson (In Elven Lands: The Fellowship)
Ainur
Glass Hammer
Nazgul
Archangel (The Akallabeth)
Ainur
Asimov:
Alan Parsons (I Robot)
Hawkwind (Robot)
Frameshift (An Absence of Empathy)
Ayn Rand:
Rush (2112, Anthem, The Trees)
Paul Gallico:
Camel (The Snow Goose)
Frank Herbert:
Dun (Arrakis, Acoustic Fremen)
Toto (Dune)
Leon Tolstoi:
Yes (Gates of Delirium)
Herman Hesse:
Yes (Close to The Edge)
Kansas (Journey from Mariabronn)
Marillion (Misplaced Childhood)
Mark Twain:
Rush (Tom Sawyer)
The Bible:
Genesis
Aphrodite's Child (666)
Jesus Christ Superstar
Various Artists (La Biblia)
George Orwell:
Pink Floyd (Animals)
Rick Wakeman (1984)
Metamorfosi (Then All Was Silent)
Hugh Hopper (1984)
Anthony Phillips (1984)
David Bowie (Diamond Dogs)
Mao Zedong:
Matching Mole (Little Red Record)
Paramahansa Yogananda:
Yes (Tales from Topographic Oceans)
Sir Arthur C. Clarke:
Pink Floyd (Childhood's End)
Tempano (Childhood's End)
Edgar Alan Poe:
Alan Parsons (Tales of Mistery and Imagination)
Jonathon Coes:
Hatfield & the North (The Rotters Club)
Sir Arthur Conan Doyle:
Nolan & Wakeman (The Hound of the Baskervilles)
Dante Alighieri:
Metamorfosi (Inferno)
Tangerine Dream (Purgatorio (Dante Alighieri - La Divina Commedia))
Lacrimosa (Inferno)
Brassè (Dante's Inferno)
Dante
Fondeira (Dante, at last)
Il Castello Di Atlante (Malebolge)
Various Artists Concept Albums (Inferno the Divine Comedy, Purgatorio The Divine Comedy)
Echolyn (Mei)
Richard Dawkins:
Frameshift (Unweaving the Rainbow)
Jules Verne:
Rick Wakeman (Jurney To The Center of The Earth)
Nemo
Bram Stoker:
PFM (Dracula)
Alexandre Dumas:
Vanden Plas (Christ 0)
Lewis Carrol:
Neuschwantein (Alice in Wonderland)
The Amorphous Androgynous (Alice in Ultraland)
Chick Corea (The Mad Hatter)
Shadowland (Mad as a Hatter)
The Incredible String Band (The Mad Hatter's Song)
Touchstone (Mad Hatters)
Bill Bruford (Fainting in Coils)
Annie Haslam (Annie in Wonderland)
Yes (We Have Heaven)
Peter Hammill (This side of the looking glass)
Nolan & Wakeman (Jabberwocky)
Thomas Eliot:
King Crimson (The Deception of the Thrush)
Goethe:
Faust
Aton's (Dr. Faust)
Art Zoyd (Faust)
H. G. Wells:
Jeff Wayne (The War of the Worlds)
Eloy
Robert Fripp (H. G. Wells)
Ammon Duul II (HG Well's take off)
Rick Wakeman (Time Machine)
Pablo Neruda:
Los Jaivas (Alturas De Macchu Picchu)
Nietzsche:
Museo Rosenbach (Zarathustra)
Ray Bradbury:
Solaris (Marsbeli Kronikak)
Hawkwind (Fahrenheit 451)
William Shakespeare:
Steve Hackett (Midsummer Night's Dream)
Genesis (Cinema Show)
Il Volo (Essere o non essere? Essere, essere, essere!)
Lana Lane (Lady Macbeth)
Henry Cow (some music for a performance of The Tempest recycled in some of their early albums)
Richard Bach:
Transatlantic (Bridge across forever)
Jorge Luis Borges:
Montefeltro (Nel Laberinto)
Genesis (Squonk)
Homer:
Genesis (The Cinema Show)
King Crimson (Islands)
Eloy (End of an Odyssey)
Vangelis (Odissey)
XII Alfonso (Odyssees)
Symphony X (The Odyssey)
Plato:
Eloy (Ocean)
Pallas (Rise and fall, Atlantis)
Claude Vorilohn (AKA Rael):
Genesis (The Lamb Lies Down on Broadway)
John Steinbeck:
Gentle Giant (The moon is down)
Camel (Dust and Dreams)
Oscar Wilde:
Dorian Gray
Il Ritratto Di Dorian Gray
Cherry Five (The Picture of Dorian Grey)
Andy Tillison
:
The Tangent (Not As Good as the Book)