Last year, a friend sent me this New York Times article by Eric Ducker about "trailerization" (check it out - it's an audio article, so you can actually hear the musical examples that he talks about). The idea is that if you just drop a popular song into a trailer for a TV show or a movie as-is, it doesn't work as well as it could if you altered it in some way. For example, pitching the vocals down, adding a lower octave doubling, and layering in low-register electronic sounds and extended string techniques to "It's Nice to Have a Friend" by Taylor Swift gives the song a creepy, sinister, sound, making it more appropriate to be used in the trailer for the horror movie M3GAN (2022), about a killer android doll. Compare that trailer to the one for The Graduate (1967), which famously used the music of Simon and Garfunkel, not just for the trailer, but for the film itself. The most noticeable difference between the use of music in these two trailers is the abrupt starts and stops in the earlier one. The first stop actually does work well, in my opinion: "The Sound of Silence" is cut off abruptly by the abrasive speech of a party guest, but the rest of the entrances and cutoffs seem jarring to an audience who has gotten used to more subtleties in song editing and remixing. The M3GAN trailer, on the other hand, has music playing much more consistently throughout, and the stops and starts are gradual, as one song blends into another, different themes are layered, and background orchestral cues are used.
In order to remix a song for use in a movie trailer, the movie studio needs explicit permission from the copyright holder of the song. In other words, this type of use is not covered by automatic licensing. According to Ducker, musicians used to shy away from giving permission for their music to be used in a movie trailer, thinking that it might be seen as "selling out." Nowadays, it's common practice for even the biggest stars (see Taylor Swift above) to do so. But this dramatic shift actually started with the use of cover songs in movie trailers, and cover songs do use automatic licensing. For a movie studio to use a cover version of a song, they need permission from the person who recorded the cover, not the original; royalties are then paid to the songwriters based on the number of times the trailer is streamed or shown in theaters. The trailer to The Social Network (2010) was underscored with a cover version of "Creep" by Radiohead, performed by a Belgian choir called Scala, and this apparently paved the way for other trailers to use interesting popular song covers. The impulse may have been due to the fact that Scala was willing to license their recording, while Radiohead was not, but ended up leading to a new trend in movie trailer music. After a few years of these different versions of popular songs were heard in this medium, the tide began to turn and popular recording artists began to want their music used in movie trailers. Thus, the trailerization remixes began.