On the humanities.lit.authors.shakespeare newsgroup list,
AJ writes: Have you considered, very speculatively, whether
there may be some influence from the Mystery Plays? The Coventry
Cycle apparently survived the Reformation for some years, and
could have been part of Shakespeare's boyhood experience. Certainly
he would have found there a workable pattern of high seriousness
and broad comedy within a large-scale structure with a single
over-arching theme.
This seems so clear to me (as a playwright/actor who has
directed multiple productions of the Cycles) that I almost
wish I had the skills and access to scholarly material to
try to demonstrate it!
Just today a theatre friend and I were talking about how
the official ending of the Cycle festivals can't have meant
that all those wonderful exciting beloved bits and speeches,
memorized by 100's of actors, just disappeared. People must
have urged their friends and neighbors to reprise their theatrical
triumphs privately, at home, and when gathered among kin or
guildmembers. Children with their aptitude for rapid memorization
surely must have learned the most spectacular speeches and
imitated well-known actions -- such as "Killing the Calf".
I performed the St Chrispin's day speech from H5 in church
last week (in connection with the choir's "Agincourt Carol"
and "Non Nobis") and ever since my grandson has been requesting
me to "Do King Harry" for him. I imagine after a few more
times through, he'll be able to "Do King Harry" himself.
by 
