Listening to The Horse Whisperer right now, and it reminded me of the days when a movie's score often showed up in the trailer for an unrelated film (in this case, it was used in the trailer for The Green Mile). I, for the life of me, cannot remember the last time I heard another movie's music in a trailer. A sad byproduct of the last twenty years, when film music has become so generic that it's pointless to lift another movie's score for a trailer or TV spot, because it all sounds the goddamn same to begin with. What was the most recent example?
That's so funny. Yeah I hadn't thought of this in ages, but it used to be a source of endless inquiries and discussion in FSM, as people asked what was in this or that trailer. Days of yore!
I can speak a little to this first hand. Three things happened in a short space of time: first, studios began restricting the use of their music in other studios' trailers. No reason to help the competition I guess. Second, the studios that were still willing to license began raising their prices significantly which made using soundtracks less attractive. Third, the creative evolved toward a more minimalist approach relying elements that could be assembled from trailer-specific libraries. When a trailer required the use of traditional music (like Star Wars or another property with a known musical signature) it just became easier for have a composer to a bespoke score and avoid all the costs and outside approvals.
I still hear famous themes or songs in trailers, but they're usually mangled up by a "trailer sound" -- Indiana Jones, Star Wars, Dune (with Pink Floyd) etc.
I remember falling in love with the music heard in a Wyatt Earp trailer and later learning on rec.music.movies or FILMUS-L that it was music from Morricone’s A Time of Destiny.
That's so funny. Yeah I hadn't thought of this in ages, but it used to be a source of endless inquiries and discussion in FSM, as people asked what was in this or that trailer. Days of yore!
Truth be told, I miss it. Film music was distinctive enough 30 years ago that a seasoned movie music fan could tell, "Hey, this is by Horner/Elfman/Silvestri...!", even if they couldn't ID the specific score being used in a trailer, but if you lifted a Lorne Balfe cue from a random movie and stuck it in another movie's trailer, would anyone notice?
This has always been my favorite example - unlike most trailers, it just lets the music play and build the tension, with no v/o or sound effects. Very effective.
(Last Of The Mohicans used for Legends Of The Fall teaser trailer.)
RUDY and WATERWORLD spring to mind as sources for quite a few trailers in the mid-to-late 90s.
I remember the MEN IN BLACK VHS has a trailer for THE MASK OF ZORRO that used THE PHANTOM, and mirroring what other's have said, when I finally watched THE MASK OF ZORRO, I was pretty bummed that that rousing piece of music was not from that film.
What was the music in the trailer for The Mosquito Coast? Very percussive and it was used in several trailers. Maybe used for Gorillas in the Mist, too?
What was the most recent example? 
