Classifying an Expense

use promotion expense, booking expense, something along those lines

Thank you for the information. 

One more question, since this is towards booking event for the Singers, would it be best to classify it as an "expense" or "cost of goods sold"?

Thank you for the information.  One more question, this expense is for an event for one of the singers he promotes, and the promoter will pay the singer based on the profit for this particular event.  Will it be ok to  classify it as an expense or will it be better to classify it as "cost of goods sold"?