Or: something to try when, after six months, you still can't get a critical mass of your student band to reliably produce the basic pitches / rhythms called for by the piece you are supposed to be working on.
1. Devise a set of hand signals that correspond with certain musical qualities agreed upon by the class (long, short, fast, slow, high, low, dense, sparse, start, stop, etc.).
2. Allow each student (in turn) to take on the role of composer-conductor.
3. Ask each composer-conductor (in turn) to direct their peers, using the aforementioned hand signals, in an improvised ensemble performance.
Maybe the resulting music is horrible. Maybe it's not. But suddenly the kids are concentrating, cooperating, and smiling. Take your victories where you can find them, and call it a day.
(Maybe this should've been "Plan A'"?)