Released Feb 21, 1998 by Columbia Japan
This box set of background music includes many previously unreleased music cues, TV edits of theme songs, sound effects (discs 8-10) and instrumental versions. It comes with a book that lists the music cues for the entire series, which you can download from this page.
Thanks to the efforts of SailorMusic.net Forums members, a fairly comprehensive listing of these Studio Library cues is available. One forum member has made audio captures of the Studio Library cues from all five seasons: RattleMan’s Sailormoon Cues