A still photograph might capture a step or pose from the choreography, but will not reproduce a substantial part of the choreography and therefore will not infringe copyright in the choreography.
The costume, however, may be protected by copyright as a work of artistic craftsmanship, in which case permission would be needed to photograph it.
Permission from the copyright owner is needed to film choreography. Therefore, if you own copyright in a piece of choreography, you can decide whether or not you will permit videos of it to be made. Even if you do not own copyright, if you have organised the concert, you may be able to prohibit filming within the hall or theatre, or make it a condition of entry that the performance not be filmed. This is unrelated to rights under copyright law.
Note that a licence may be required from the Australasian Mechanical Copyright Owners’ Society (AMCOS) to film a performance if the music accompanying the performance will also be recorded. This licence is in addition to the venue’s licence from the Australasian Performing Right Association (APRA) for the public performance of the music.
You should also get permission from the dancers to film the performance, as they have separate rights under the Copyright Act as performers.
As with any other copyright work, if important or distinctive parts of your choreography are reproduced, performed or broadcast without permission, you are entitled to take legal action for damages or other remedies.
Whether or not permission can be withdrawn depends on the terms of the agreement with the copyright owner. It is advisable to make these terms clear at the outset.
You should be aware that if a person has relied on the permission (for example, by spending time and money on preparing the production) the copyright owner may not be entitled to withdraw permission at a late stage.
If you feel that your reputation or honour may be damaged by the standard of performance, you may possibly be able to take action on the basis that your moral right of integrity will be infringed if your choreography is used in the production. This may, however, be difficult to prove or show. (Particularly in relation to performances by children, in dance schools or in the amateur context, it may be that your claim is met by an argument that any infringement is “reasonable” in light of the available resources and skills).
The school will need to work out who owns copyright in the choreography. If the teacher owns copyright, the school will need to assess whether or not it retains a licence to teach and perform it. If the teacher was an employee of the school and created the work as part of his or her job, the school owns the copyright.
On the other hand, if the teacher was a freelancer, and was commissioned to create the choreography for the school, or created the choreography as an addition to his or her duties as an employee, the teacher will own copyright (unless there was an agreement to the contrary). If the school does not own copyright, it may nevertheless have a licence to use the choreography for the purposes that have been agreed. In many cases, however, it may be difficult to work out whether a school has a licence or not, particularly if the teacher created the choreography only for his or her class or classes.
Where a teacher creates choreography for use in a school, it could be in the school's interests to have an agreement allowing the school ongoing use of the choreography. From the teacher's point of view, however, there may be benefits in permitting the work to be used by the school only from year to year (so that the teacher can terminate the permission after leaving the school). In any case, it is preferable for the teacher and school to have whatever is agreed set out in writing.
There is an important distinction between using a person’s ideas and reproducing a substantial part of their copyright work. You can develop choreography using the same underlying theme as another work (for example, the seven deadly sins), and may be able to use a particular move you have seen in someone else’s work, without infringing copyright. However, if you perform someone else’s copyright work without permission, you are unlikely to avoid infringing copyright simply by making a few changes to it.
Note that making alterations to another person’s choreography could also be an infringement of the choreographer’s moral right, if you fail to attribute them for what you have taken from their work.