Most likely a classic 419 - the cheque will be for more than the amount you charge and then you will be expected to give them the change. Of course the cheque is fraudulent, but you won't know that til they're long gone with your money.
I've noticed more and more specific ones going out - modelling ones to models, music ones to musician. Do you have a profile in a music teaching directory online somewhere? They probably harvested your details from there.