I decided to have a listen (on the Beeb’s new “Sounds” page) to BBC Radio 3’s “Jazz Now” programme from December 17th. As they played a few excerpts from this and spoke to TV historian Helen Wheatley at Warwick University, I realised I’d missed an important 2018 archival album and film.
The album has been released on CD and as a set of FLAC files by the Storyville label. “Duke Ellington In Coventry 1966” is over an hour of delightful live Ellington music.
The concert was originally broadcast on ITV’s midlands franchise of the day, ABC, in black and white. It was thought lost for the past 52 years but was unearthed in time to become part of the buildup for Coventry’s “City Of Culture” celebrations in 2021.
The film is being screened today in the cathedral and will doubtless be released generally soon.
https://www.coventrytelegraph.net/news/coventry-news/jazz-duke-ellington-coventry-cathedral-15478366

Now that was a discovery! They sound in fine form.
I had to find out more. As the review below mentions, Coventry Cathedral was not reopened until 1962 and was a prime mover for reconciliation in the post-war years.
http://www.jazzviews.net/duke-ellington—in-coventry-1966.html
I presume you have Ella’s Live album recorded in Stockholm that same year. It’s Duke’s orchestra backing her but his rhythm section, including himself, are replaced by Ella’s trio for six of the nine tracks.
Duke toured Europe in 1966. My dad saw in him in Liverpool that tour (actually, just checked, he saw him in 1967). Duke met up with Miró as well, neither being able to speak each other’s language but communicating by other means.
Also interesting to me is that the choir used for the concert were the Cliff Adams Singers, known principally in the UK at the time for “Sing Something Simple” on the BBC Light Programme.
There was nothing simple about what they were singing on this gig.