Posthumous Collaboration

"...if [George R. R. Martin] dies early, Hollywood will pay somebody a lot of money to finish the books from his notes. Probably Brandon Sanderson or Kevin Anderson or someone whose name rhymes with either of them. If you’re a fantasy writer looking to make it in the big leagues finishing other peoples’ work, you could do worse than to change your name to “Ganderson.”"

- Mighty God King

Author Existence Failure can be a sad thing. When a famous author dies and they leave only partly-completed works, never to be finished or seen by the general public. Or will they?

A Posthumous Collaboration is when an unfinished work is completed by someone else for the sake of the publisher's bank account fans.

The new author may have been close to the original one, or even helped with the work while the original author was alive, or just working off some discovered notes on what the original author had planned, but what's important is that the work has to have already been started by the original author before their passing; it doesn't count if someone just creates a brand new work using the dead author's characters or universe.

See also Literary Mash Ups.

Art

 * Garfield Visits Rockwell, a calendar which remedies the lack of fat orange cats in Norman Rockwell's paintings for the Saturday Evening Post.

Film

 * A.I.: Artificial Intelligence was started by Stanley Kubrick and finished by Steven Spielberg.
 * This one is a bit special, as it was started by Kubrick, who then handed it to Spielberg, with plans to direct it. But once Spielberg did it, it was always he who was to direct it.
 * After the Rain was written by Akira Kurosawa, who was planning on directing it; after his death Koizumi Takashi took over.
 * A variation of this occurred with The Imaginarium of Dr. Parnassus. Heath Ledger passed away during filming, so Johnny Depp, Jude Law and Colin Farrell stepped in to play the same role and help finish the film.
 * The songs for The Shocking Miss Pilgrim and Kiss Me, Stupid were written George and Ira Gershwin after George's death.

Literature

 * The Gathering Storm, Towers Of Midnight and A Memory Of Light by Robert Jordan and Brandon Sanderson
 * Thrones, Dominations by Dorothy L. Sayers and Jill Paton Walsh
 * Sayers' translation of The Divine Comedy was completed by Barbara Reynolds.
 * Fall of Kings by David Gemmell and Stella Gemmell
 * The Wanderer by Cherry Wilder and Katya Reimann
 * The Children of Hurin and The Silmarillion, by J.R.R. and Christopher Tolkien
 * Hooray For Diffendoofer Day by Dr. Seuss and Jack Prelutsky
 * Variable Star by Robert Heinlein and Spider Robinson, working from copious notes
 * Grumbles From The Grave by Robert and Virginia Heinlein
 * Garden Of Shadows and Fallen Hearts by V. C. Andrews and Andrew Neiderman
 * Antagonist by Gordon R. Dickson and David W. Wixon
 * Saint Leibowitz and the Wild Horse Woman by Walter M. Miller, Jr and Terry Bisson
 * Eternity; Home, Sweet Home 2010 A.D.; The Other Time; Trojan Orbit; Deathwish World: Mack Reynolds and Dean Ing
 * The Double Tower; Prince Alcouz and the Magician; The Scroll of Morloc; The Descent into the Abyss: Lin Carter and Clark Ashton Smith
 * Nekht Semerkeht by Robert E. Howard and Andrew J. Offutt
 * Psychoshop by Alfred Bester and Roger Zelazny
 * Donnerjack and Lord Demon by Roger Zelazny and Jane Lindskold
 * Poodle Springs by Raymond Chandler and Robert B. Parker
 * The Watsons by Jane Austen and Catherine Hubback, John Coates, Laura Wade, or Helen Baker ; each one showed up with a different version.
 * Through the Ice by Robert Kornwise and Piers Anthony
 * In this case, the living author is actually the more famous one.
 * Whistle by James Jones and Willie Morris
 * The two concluding books of the Dune series, Heretics of Dune and Sandworms of Dune, supposedly based on Frank Herbert's notes, written by Brian Herbert and Kevin J. Anderson.
 * The prolific David Foster Wallace left a large cache of notes behind before he died and so others were able to step in and finish his long-awaited novel, The Pale King.
 * When young adult author John Bellairs died, he left behind two unfinished manuscripts and outlines for two other stories. The finished versions of those four books, completed by Brad Strickland, were so well-received that Strickland has since been commissioned to write several more books in the series.
 * E.B. White, up until his death, kept adding to and revising William Strunk's The Elements of Style, to the point where he was even credited as a co-author. Now since White's own death other editors have been doing the same, uncredited.
 * "The Shuttered Room" and certain other fragmentary stories were completed after H.P. Lovecraft's death by August Derleth.
 * David Gemmell died in 2006, leaving the final volume of his Trojan War saga unfinished, but with notes to complete the work. His wife Stella was credited as co-author of 'Troy: Fall of Kings.'
 * The Family, a novel about The Corleones The Borgias, by Mario Puzo, was completed after his death by his girlfriend Carol Gini. Notably, the last chapter features a woman mourning the death of her lover

Music

 * Requiem by Wolfgang Amadeus Mozart and Franz Süssmayr
 * Symphony no. 10 by Gustav Mahler and Deryck Cooke
 * Free as a Bird and Real Love by John Lennon and the rest of The Beatles
 * In this case, the songs were credited to the Beatles and not John Lennon. It still counts as this trope, though.
 * Brainwashed by George and Dhani Harrison and Jeff Lynne
 * Made In Heaven by Queen was this on purpose, as Freddie Mercury didn't think he had enough time left to create whole songs (and he was sadly correct); so he just did his parts and let the rest of the band finish them after he died.
 * In Your Life and Take Me to Heaven Tonight by Melanie Thornton and the rest of La Bouche
 * Countless posthumous collaborations between Tupac Shakur and others, eg "Pac's Life" with Ashanti and T.I.
 * Country singer Keith Whitley's posthumous tribute album has the usual famous stars' covers of songs (including "When You Say Nothing at All" being Covered Up by Alison Krauss), plus never-released studio tracks, plus a duet with his widow Lorrie Morgan that fits this trope.
 * And taking it a step further, a DJ spliced the Alison Krauss version of "When You Say Nothing at All" with Keith Whitley's.
 * Adagio in G Minor by Tomaso Albinoni and Remo Giazotto.
 * The Mermaid Avenue albums by Billy Bragg and Wilco, which set old unpublished Woody Guthrie lyrics to new music.
 * Dropkick Murphys also set unpublished Guthrie lyrics to new music, first with "Gonna Be A Blackout Tonight", then with their Signature Song "Shippin' Off To Boston".
 * Although not nearly as many as Tupac yet, Ol' Dirty Bastard has also had a steady stream of posthumous guest appearances. And while it was released while he was still alive, the album The Trials and Tribulations of Russell Jones was made without his involvement while he was in jail: acapellas from unfinished songs (or sometimes even previously released songs) were set to new beats, with many guest appearances filling in the gaps.
 * After Johnny Mercer's death, lyrics of his were set to new music by Barry Manilow.
 * Nico by Shannon Hoon and the rest of Blind Melon.
 * Hank Williams Jr did this twice with his father Hank Williams Sr. One time, he corralled his son Hank Williams III into doing an album called Three Hanks: Men with Broken Hearts, which combined previously recorded vocals by Hank Sr. and newly recorded vocals by Hank Jr. and Hank III. Hank III doesn't even acknowledge this album's existence, because perhaps he agreed with a reviewer who deemed it morbid and unnecessary. Hank Jr. also did a song called "There's a Tear in My Beer", which incorporated a vocal track recorded by his father. The video digitally inserted Hank Jr. into a performance of Sr.'s.
 * Similarly to the Hank Williams example above, "Unforgettable" by Nat "King" Cole and Natalie Cole, and "God Bless the Child" by Billie Holiday and Tony Bennett.
 * Lynyrd Skynyrd did this with "Travelin' Man". Ronnie Van Zant's vocals were lifted from a live recording of the song and mixed into a duet with his brother.
 * "What a Wonderful World" by Louis Armstrong and Kenny G, which Pat Metheny really didn't care for.
 * Yo Yo Ma's venture into tango music includes a track on which he "collaborates" with deceased tango legend Astor Piazzolla using preexisting recordings.
 * Michael Jackson's segments from "We Are The World" were re-used on the 2010 remake for Haiti, given his then-recent death and his heavy involvement in the original. Janet Jackson even sang along with her late brother in the remake.
 * "Hold My Hand", featuring Akon, was Michael's last known song before his death.
 * Japanese R&B singer Ken Hirai has a "duet" on his Cover Song album Ken's Bar with noted Japanese pop singer Kyu Sakamoto, who died about 20 years before the album was recorded, covering Sakamoto's song "Miagete Goran Yoru no Hoshi wo".
 * In 1969, Bob Dylan and Johnny Cash recorded a version of the former's "One Too Many Mornings", which was often bootlegged, but never really saw official release. The 2012 Bob Dylan tribute album Chimes Of Freedom took this recording and added some additional vocals by The Avett Brothers. Kind of an odd example, as the song wasn't "unfinished" to begin with.
 * Six months after the death of rapper Lisa "Lefteye" Lopes, TLC's fourth album 3D was completed by the remaining two members with posthumous vocals by Lopes on four of the songs.