My parents wont support me in my decision?

i want to sing and i know my parents approval comes first but it is what i want in my heart and they don't support me in my decision. i am only 13 and i am not choosing this as a career path but it is my dream. i don't have the best voice in the world but my friends sisters and i believe it is pretty good and my dream is to make my voice known to others. my parents think that i will become caught up in singing and hope to be famous. they let me enter in the talent show but it turns out the talent show was canceled! they love to hear me sing around the house and although this objection was not voiced i know they think singing for others is considered unbecoming for a young lady. what should i do?