Extracting Vocals without the Instrumental

As the title says i don’t have the instrumental. The file is a speech from a trailer and i want to cut the music and keep the vocals. The song is mixed for the trailer, so i doubt i can find it( i tried). Any ideas on how do i keep the vocals?

You probably can’t do that, but see this article: http://manual.audacityteam.org/man/Tutorial_-_Vocal_Removal_and_Isolation (vocal isolation is discussed near the end)

thanks i’ll try it