Videomaker – Learn video production and editing, camera reviews › Forums › Specialty Topics › Wedding and Event Video › legality of filming a high school musical › You can try asking for, an
You can try asking for, and sometimes actually receiving, permission from the copyright holder of the play that HAS been approved for performance. (sometimes purchase of the script by and for the school includes a “performance rights” clause)
That permission (look through the existing release wording, if any) would be to allow the creation of a video for “educational” purposes. Even this has been taken to the extreme, but it might allow for some flexibility in seeing that each performer received one to “study and learn” from – a kinda sorta loophole that some have utilized for getting around the production, sale and distribution issues.