Failiing her being able to use the original Loverboy I think All My Life would have been a great start for her... wouldn't have been that pop success out the gate but may have eventually crossed over. But it would have really signified that it was Glitter was period piece and something a bit different for her.
Also, I live for All My Life and think it's amazing that Mariah worked with Rick James.
''All My Life'' is the better song, sure, but its commercial appeal was even worse then LB imo.
The good thing about releasing AML instead as the first single would be, as you said it, to emphasize that Glitter was a soundtrack from a movie set in the 70's.
But let's face it, Mariah did Glitter more as an album than a soundtrack, it is ALL her!
She really did though... She tried it!! lol I guess she thought she would get fans to buy it if she sold it as a Mariah Carey album with an 80s motif - which it was - a mixture of fun uptempos and ballads and especially given the autobiographical elements of the movie...But then it became strictly a "soundtrack album" when it all went down the toilet!
Yes, I loved how she did a complete 180 on Glitter by a year later. In 2001 she had been selling it as it a straight up Mariah Carey album. She was very clear about that. A full campaign disaster later, it was "just a soundtrack" A shame she really seems to have disowned it so hugely and its never really sweetened over the years, unlike say, the CB album which she will still credit the material and various songs on it.
While I can't really get into Glitter, there are some nice little tracks on there and she sounds glorious on a lot of the tracks.