All right, I guess it's time to give the answers. 27/36 were found (including 22 with the location), which I guess is good.
So let's see:
Found (22)
01. The Beast Within, The Opera [KriD]
02. The Curse of Monkey Island, A pirate I was meant to be [KriD]
03. The Dagger of Amon Ra, Luigi [ollie]
05. The Neverhood, Main Theme [AFGNCAAP]
08. And Then There Were None, Chapter Start [ski]
09. Sanitarium, The Mansion [ollie]
10. The Pandora Directive, Sad News for Regan [KriD, ollie]
11. Myst, Introduction [ollie]
12. The Moment of Silence, Launcher music [KriD]
15. Grim Fandango, Maximino [Huz, Kontra]
16. Conquests of the Longbow, The Pixie [AFGNCAAP, Ledz]
17. Myst IV, The Camoudile [ollie]
18. The 7th Guest, Coffin Dance [ollie]
20. The Last Express, Duel atop the Train [Fienepien]
22. Leisure Suit Larry 6, The Swimming Pool [Ledz]
26. The Legend of Kyrandia 3, Fish World [ollie]
28. Discworld Noir, The Archeologists' Guild [KriD]
30. Indiana Jones and the Fate of Atlantis, Atlantean Canals [Ledz]
31. Faust, Chapter 3 [AFGNCAAP]
32. Syberia, Komkolzgrad [KriD]
34. Fahrenheit, Say Goodbye [AFGNCAAP]
36. Monkey Island 2, The End [KriD]
Missing / incomplete ones
#4 was hard, for reasons explained in post 43. It's the underwater music from
Operation Stealth, where you're supposed to avoid sharks, and spend hours looking for a rubber band.
#6 was tricky too. It's Strauss'
Blue Danube, that can be heard in
Alone in the Dark. It's one of the records you can use to try to get the ballroom ghosts to start dancing -- but only the
Danse Macabre works!
#7 was indeed from
King's Quest V, but it was Queen Icebella -- who was voiced by Lori Ann Cole in the CD version.
#13 was from
Prisoner of Ice, as AFGNCAAP guessed; it plays in the museum.
#14 is from the title theme of
Maupiti Island. I think that's the Atari ST version; the PC one doesn't sound nearly so good.
#19 should have been fresh in people's minds, since it's from
Dreamfall. It's Kian's training session in Sadir.
#21 was just a few notes long. It was taken from the spaceship fight in
Rex Nebular (both in the intro and finale).
#23 was Dr. Fred sleepwalking in
Day of the Tentacle.
#24 was the chase with Sordid's apprentice (Runt) at the end of
Simon the Sorcerer 2.
#25 was tricky. It's played in the cabin of Rebecca Karaboudjan, in
Cruise for a Corpse. Except that, in the game, she immediately starts talking to you, letting you only hear the first few seconds of the music, which I (of course
) didn't use for the medley.
#27 seems to be the main theme from the first Lost Files of Sherlock Holmes, but it's actually taken from the second one (
The Case of the Rose Tattoo), when you meet again a character from the first one: Rose Hinchem, a.k.a. Madame Rosa.
#29 was from
Dune; it's a frequently-used theme, most notably when looking at the globe, reading the book, and during most cutscenes. The enhanced version used here was taken from the
Spice Opera soundtrack CD.
#33 was Lucreto's theme from
Mask of Eternity.
#35 was a final trick. It's from
Gabriel Knight 3, and is definitely a surprising arrangement of the Schattenjäger theme (used in all three games). The trick was that, while found in the game's data files, this version in never actually used in-game.
And that's it. Many thanks to all those who took part in the game!