Queens Road Gaiden is a radio drama that was broadcast during the Shinnosuke Furumoto radio show starting in October 1996, five months before the PS1 game (which is just called Queens Road) was released:
https://ja.wikipedia.org/wiki/古本新之輔のパラシュート遊激隊. This is the drama soundtrack.
I am
not sure if the game's vocal themes were also used in the radio show, or if they're just on these two drama albums as a bonus. The "game version" subtitles on the other album may suggest the latter.