here), as well as permission from the school band performers and conductors (to avoid right of publicity claims). Since sync licenses are so difficult to obtain, we believe you can probably protect yourself just as well by getting a mechanical license instead of sync license. (Mechanicals are used only for audio recordings, syncs are for audiovisual recordings.) That would deflect any disgruntled publishers ... though we doubt any would want the negative publicity resulting from a brouhaha with a high school band.
Practically speaking ... If you are only selling the disks locally to members of the community, you can probably forego most of the permissions mentioned above. (It's what often happens when a tree falls in the intellectual property forest.) It may help to have something in writing (emails are fine) between you and the school that indicates you have their permission for your endeavor. If you intend to sell to a broader audience, you will probably need to get the permissions discussed above (and described in detail in the Getting Permission book.)