Deryk Barker wrote in response to me:

>>The most interesting video version I've seen of the Britten was made by Sir
>>Malcolm Sargent with the London Symphony Orchestra in 1947.  He provides a
>>fine introduction, conducts, and serves as narrator.  ...
>
>Was this not, in fact, the very purpose for which the piece was written?

Yup.  In fact, its concert premiere was given by Sargent with the Liverpool
Phil on 15 October 1946, and the film released the following year.  Alas,
Purcell himself was in no shape to collect royalties.

Charles Barber