Here is a response I gave to a Choral Music Educator who is leading a weekend Honor's Chorus type event as a guest conductor. He has limited experience working with middle school children:
My biggest words of advice:
Talk less. Do more.
Following those guidelines will help you tremendously.
For future reference...When I plan my work for festivals like the one you described, I also make sure I pick at least one piece of music that fun. For example, I like incorporating a song that has some movement in it. Picking at least one pice that is a bit crazy and non-traditional helps the rehearsal process with this age group in this setting. For example, I chose "Coffee Break" from How to Succeed in Business Without Really Trying. They loved it. I also like to make sure the rehearsal periods aren't overly long and are planned with sufficient breaks, and if I feel that I'm losing them, I am not afraid to break early. Continuing a rehearsal that has lost energy sucks the life force out of this age group. Feel the energy and don't be afraid to respond to it.
My blog for middle school teachers:
My Middle School Sight Singing Program:
My YouTube Channel with Teaching Tips: