Composer change from the first film
Elmer Bernstein had written the score for Ghostbusters (1984) but did not return for the sequel. The reason given is that Bernstein, an established film composer, wanted to step away from a run of comedy assignments and take on a serious dramatic film instead, so he passed on scoring the sequel.
Randy Edelman wrote the replacement score. His instrumental cues accompany the film throughout, separate from the pop songs that were issued on the tie-in album.
Lack of an official release
Edelman's score for Ghostbusters II has never been released on its own in any official form. No commercial album, CD, or download has presented the instrumental cues as a stand-alone product. The contemporary tie-in album was a song compilation rather than a score release, so the underscore has remained available only as heard within the film itself.
See also