To be a 'fly on the wall' is just a metaphor. I get it, but...

 I certainly would have liked to have been 
a fly on a wall somewhere near this... 

And I'm not that big a fan of the band.

 

This rooftop gig was the final public performance of the Beatles. On 30 January 1969, the band, with keyboardist Billy Preston, the Beatles surprised a central London office and fashion district crowd with an impromptu concert from the roof of the headquarters of the band's multimedia corporation Apple Corps at 3 Savile Row. In a 42-minute set, the Beatles played nine songs before the Metropolitan Police Service asked them to 'reduce the volume'.

Footage from the performance was later used in the documentary film 'Let It Be'.

 

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