Q: Can we use pre-corded music in our school's promo film that goes to prospective parents and is on the website?
A: Yes you can; but you need to check if the music is 'in copyright' andf if it is do you need to hget permsssion. If you need permission then you will have to 'write' and ask and w await the reply. If you haven't got time then look for other music that doesn't require to ask. If you have got the time try it; sometimes the answer will be 'No!" or there will be a charge - but some times if you explain your use of the material, how it will be published and for how long - you never know they might just say 'Go ahead!'.
See this section Collecting Societies
Q: Do I needs a licence for music on a podcast?