class ConcertTrackerApp:
    bands = []
    musicians = []
    concerts = []

    def create_musician(self, musician_type: str, name: str, age: int):
        pass

    def create_band(self, name: str):
        pass

    def create_concert(self, genre: str, audience: int, ticket_price: float, expenses: float, place: str):
        pass

    def add_musician_to_band(self, musician_name: str, band_name: str):
        pass

    def remove_musician_from_band(self, musician_name: str, band_name: str):
        pass

    def start_concert(self, concert_place: str, band_name: str):
        pass