You should definitely get the permission of the creator to use it.
I've joined a new school and one of the other girls has asked if I'd do a duet with her. We're spookily well matched (I actually got mistaken for her at a performance the other week), so we'd make a good duo.
We've started talking about what to dance, and she sent me a couple of Youtube clips saying "I like this music". However in discussion, it's becoming clear that she's not just talking about the music - her intention is for us to copy the whole choreography from the Youtube clip.
I feel uncomfortable about that, and I'm not sure if I'm right to feel that way, or if I'm just being pedantic. After all, we'll only be performing at our school hafla so it's not as if it's a big deal. Still don't feel quite right about it though. Thoughts?
Since a school hafla come under "education" and you aren't making money from it, I'd say give credit where credit is due and not worry too much about it.
"Well, now that we have seen each other," said the unicorn " if you'll believe in me, I'll believe in you."
Absolutely give credit and if you ever decide to perform it anywhere besides a school hafla get permission first.