What's that Secret You're Keepin'

I had a meeting in Holmfith this morning. There's all kinds of "Summer Wine" touristy things here to blip, but I've settled for this lovely, old, ornate green door that I passed on my way.

Makes me think of the Shakin' Stevens song

Green door, what's that secret you're keepin'?
Wish they'd let me in so I could find out what's behind the green door.

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Update:

Following your comments I've just done a bit more research on this.

Honestly, I don't remember Frankie Vaughn singing this (for goodness sake it was released in 1956!).

I've also just found out that, according to Mr Google, the "Green Door, as referred to in the song, actually exists on Bramerton Street, just off the King's Road in west London. It's now painted blue and is a storage space for a nearby dress shop. The door in the lyrics was the entrance to one of London's first lesbian clubs - "the Gateways" and the song is actually about a man trying to get into a lesbian bar.

So if you believe all that, there can't be another song that has been played so widely, without anyone knowing what it's really about.