My husband has been working with a few students for several months on this adaptation of Shakespeare's Julius Caesar. Nobody else (including me) had seen it until yesterday at our graduation ceremony, and we were all completely floored by the maturity of the performances and the sheer amount of memorization. The editing of the play consisted only in choosing the three scenes most important to the plot-- there was no "dumbing down" of the language at all.
You can watch it in this series of videos taken by a parent. Altogether it is about 45 minutes long.
Brutus is in 4th grade, Antony and Cassius in 6th, and Metullus Cimber and Caesar in 9th. I have seen a lot of children's theatre and although I am partial to these kids, and I like Shakespeare better than The Wizard of OZ, I must say that I have never seen such sensitive performances with such rich material.