And it’s been pointed out that that statement is a fallacy!
Carnegie Hall is a ‘For Rent’ establishment. Anyone can perform there if their check clears.
Is it possible that Il Maestro was making a joke?
What performing artist rents a concert hall? If he’s an unknown talent, that’s taking a big chance that ticket sales will cover the rent.
Usually, an impresario notices their talent & adds them to the playbill. Getting noticed is what requires practice.