First off, I love this song. 

I was listening, and noticed at 1:30 into it, there is a "call and response" type inter-weaving of two vocals. My question is, is it Barbara Mason and a backing vocalist? Or is it two tracks of Barbara's vocals laid down on top of each other? I am trying to listen and see which vocal does not sound like her, but they both do (to my ears). 

This led me to re-listen to the whole song. It sounds like there is echo or (some kind of reverb or something?) on her vocals throughout. Maybe they recorded her singing the same thing twice exactly the same and laid them on top of each other? (I know in rock music, they have guitarists play the same thing multiple times and lay all the tracks into the song to make it sound "thicker").

Maybe I am totally crazy here (I have no experience in production/recording). Just curious.   

 

 

 

Always been since my teens to this day a very strong firm favorite in my heart and on my deck. What a fabulous cheap and cheerful beautiful 45 to look and listen to. Every home should have one.

FWIW I am certain that her singing was taken over/re-recorded to give that slight off-sync/off-set vocal shrill effect and allowing her own choruses/answers/echoes toward the end to great effect IMO. 

Yes,definitely Barbara backing herself with overdubbed vocal ad-libs in the last section of this fine 45'. Philly Doo-Woppers The Larks(with Weldon McDougal) backed her on an earlier 45' but Barbara is on her own here

 

 

Her early Arctics are backed by the Tiffanies.

Sounds like Barbara to me