Is Varispeed used on song Don't Speak - No Doubt

At your risk. By listening to the CD single, the famous track sounds on C minor. Then track 2, the simple kind of demo version sounds on B minor. On Bminor the voice is more like the voice of a normal human being, and it sounds a bit out of tune, ie a bit lower in pitch than needed. So a special Tascam bass player practice CD player was used to Change the not so nice B minor track to C minor and it immediately sounded more ethereal , the singer younger due to time antiexpansion, plus the voice more in tune. Simmilarly the good Cminor master was changed to B minor and it sounded much inferior. Same experiment was done with radiohead, for example Creep. if playback is reduced by 1 semitone the excellent singer sounds still excellent but more like a normal human being. Do these experiments sugest that in some cases when the singer is to sing, the pitch of the backing track is reduced by 1 semitone, then at playback back to normal so effectively only the vocal is increased by 1 semitone with corresponding change in timbre. Listen also to To France, Moonlight Shadow - Mike Oldfield, Christophe, Demis Rousos, Sleeping Satelite - Tasmine Archer, ABBA. So far i have found bibliographic evidence only for ABBA, the book Good Vibrations-Mark Cunningham.