This is interesting, just stumbled upon it in an interview about the audio for the new Indiana Jones game:
The soundtrack is composed of about 40 minutes of brand new tracks created by Gordy Haab and Ray Harman. The rest of it (hours of it) is made up of never-before-heard music from the days of Raiders and Temple of Doom. We wanted to keep the feel of the old movies, but we didn't want to beat you over the head with the old music. It strikes a great balance.