Answer:
They should make an argument that rap is music and provide justification
Step-by-step explanation:
Two musicians are discussing whether rap counts as music. In order to come to a conclusion, they decide to ask, "What is music?"
In order to continue their philosophical inquiry, their next step should be to make an argument that rap is music and provide justification.
This is because, a philosophical question does not have a yes or no, or right it wrong, rather it is meant to be debated to arrive at a conclusion.