If you know a professional photographer or videographer, you may want to recommend him or her to the principal. Another option would be to see if you can form a partnership with a local media center. The grade school my brothers attended had such a partnership. Seventh and eighth graders could take a class as an elective and learn how to use the television cameras, sound equipment, etc. Their final project was recording the winter and spring programs each year. It allowed the students a great experience, gave the parents a low cost option for a very professional video (the teacher of the class ran the show, so the videos were always very high quality), and it made the school a little bit of money ($2-3 on each copy sold).
The thing that gets to me is that although we are a small community and money is very tight .. up on one wall is a video set-up for taping the basketball games. Someone must know how to use it .. and we certainly could use the money from video/stills sales. We have a "donate cookies" sale before the concerts .. you buy what others brought for whatever you want to pay. That money is split between the 2 grade schools (1 is preschool thru 2nd and the other is 3rd and 4th grade).
I'd much rather see 1 person up front snapping/videoing pix than what happens now. Especially since my niece had to walk between the first set of chairs and the 4th graders sitting on the floor to get a picture. The other parents either snap away (with flashes) all during the concert or, a few, line up to one side and shoot.
Unfortunately this year they had the kids on the court floor (on a tier) rather than up on the stage. They only had 1 side of the bleachers down. The ones facing the kids.. er.. like this:
kids on a tier, facing south
kids on floor, facing north
2 rows of chairs
So unless you stood in front of people there wasn't a good way to get decent pictures. My pix last year (from my seat) were blurry (the kids were walking in front of me), odd colored from other flashes messing with my adjustments and just too far away to get any detail.
I think the next time I see one of the principals I'll suggest a videographer or your suggestion above of involving the bigger kids .. my kids have 12 more years to go at this community (one is a kindergartner) and it would be nice to have pretty photos to share with their grandparents and to have for myself.