If the market for concert tickets is in equilibrium and the fire marshal tries to reduce the number of tickets sold,all other things equal,total surplus will decrease.

If the fire marshal tries to reduce the number of tickets sold, it would result in a decrease in the quantity of tickets sold, causing a shortage. This would result in an increase in the price of tickets and a decrease in consumer surplus. Producer surplus may also decrease due to the reduced number of tickets sold. Overall, this would lead to a decrease in total surplus.