The movie was The Most Reluctant Convert, an adaptation of a one-man stage show retelling C.S. Lewis's Surprised by Joy. It's very stagy, consisting mostly of Max McLean, who looks very much like the middle-aged Lewis, at least once he's in makeup, giving the lengthy narration as he wanders around Lewis sites in Oxford (including his house, the Kilns) and often in and out of flashback scenes without interacting with the other characters. McLean at least speaks his part well, and the scenery and flashbacks provide variety and verisimilitude. Naturally there is absolutely nothing about Mrs. Moore, though there's a rather odd emphasis on Lewis's early adolescent crush on his dance teacher.
A few thoughts while watching the movie:
Did Kirkpatrick actually call himself The Great Knock?
If Lewis really didn't care for Virgil, why did he go on to translate much of the Aeneid?
Did Tolkien give Lewis the idea for his Trilemma?
Why would Lewis doubt Tolkien remembered their Addison's Walk conversation? Tolkien recast his argument on that occasion into a long poem; surely Lewis was able to read it?
The concert was pianist Federico Colli at Herbst: young, slightly built, pointy-bearded. He played Bach, Scarlatti, Mozart, and Schubert, and he played them all in a very odd manner: grabbing, or in some cases creating, slow introductory passages which he played at an exaggerated crawl and very quietly, while hesitating over, delaying, and even eliding entire notes.