The Three Degrees at The Royal Albert Hall was a 1979 television special produced by the BBC. It was a live concert performance by the American female vocal trio The Three Degrees, who were backed by the London Philharmonic Orchestra at London's prestigious Royal Albert Hall on 8 October 1979. This was The Three Degrees' second television special.
The Three Degrees were not native British citizens. 
It states that they are an American group. 