I particularly loved them because in the summer of 1986, when I had an accommodation crisis, they took me in, no questions asked, as an non-paying guest in their home for two months. Their son Vincent, now a musician in his own right, was travelling so I was able to stay in his room. I was 19 and must have been really annoying.
But Colin was always mellow, especially after his evening joint - the first time I'd seen anyone use marijuana. Their household also included a cat, by the name of Pink Floyd, who enjoyed the attention I gave. ("Do you think it's legal", Colin asked Shirley, indicating me and Pink Floyd, "for a chap to marry a cat?") I taught them to play Dampfross, the German version of the great boardgame Railway Rivals, and Shirley won every time. ("Next thing", said Colin, indicating me to Shirley, "he'll suggest we start playing for money.") In return they demonstrated the virtues of hospitality and generosity. And they had a wonderful collection of novels of varying degrees of quality.
Shirley's vocal chord problems meant that she wasn't performing professionally, but they would occasionally do a bit of jamming in the evening, to keep their hand in. Colin had a regular weekly TV spot. as well. Sadly there is no video of them together, but here's an audio of their performance of "The Family of Man", one of their standard numbers, matched with pictures of the two of them at the height of their career.
Here's Colin on his own performing "One More City" in 2003.
I lost touch with them after I left Germany in 1986, but was very glad to renew contact with Colin via Facebook in the last few years. They were a tremendous couple, and the world is poorer without them.