Written at the age of 18 years old and performed here at the age of 19. It's a remarkable song if only for the way Kate Bush squeezes the lyrics and syntax to achieve something different for "so cold, let me in your window" with emphasis on the second syllable of the last word not the first syllable as would be expected.
As soon as I understood what she did just now here, I realised it was as pure as art gets in a singer, song writing (not forgetting interperative dance) and then I thought of the parallels (lines) with Debbie Harry's lyrical contortions and Mezzo Soprano vocal transitions in Heart of Glass that made the song worth posting too. They both sing of the love/hate dynamic often found between lovers, which I have to say I'm not a fan of in real life, but recognise as productive and useful in many relationships I've observed.
Whatever you think of these two songs I've yet to hear someone sing them so that they are indistinguishable from the original. If you do let me know.