They follow the same pattern. In the first half he lectures about the piece with demonstrations on the keyboard and by the performers. He'll play a passage in a boring fashion and then show what the composer did to make it more interesting - e.g. major/minor keys, surprising notes, rhythm changes, etc.
Then after the intermission the piece gets performed in whole. And then he and several of the performers sit on the stage to answer questions from the audience. The last question was to the choir director about auditioning and how he chooses who is in the chorus. He said if the person really wants to be in the group, can sing, and will commit to doing the practicing, all the rehearsals and performances they are in. I like that attitude and it reminds me of the approach that the late Marleen Montgomery who was the director of The Quadrivium - an early music group that no longer exists - that I was a member of for a bunch of years. She really brought the best out of people. Some of the people have gone on to have serious careers.
The Ceremony of Carols is based upon some late medieval carols. My absolutely favorite one is There is no Rose. And it brings back another memory. When I was in 8th grade I had a role (I don't remember the role - it was a while ago...) in the Annual Christmas Pageant. What I do remember is the High School (girls only at the time) Chorus used the Britten work for the music and I can still remember the sound of There is no Rose.
Here is Chanticleer singing the early version:
And here is the Britten version: