The energy of the air around the drum is the sum of its kinetic and potential energies. Before the drum is struck, the air is at rest, so its kinetic energy is zero. The potential energy of the air is due to its pressure. The pressure of the air is higher before the drum is struck because the air is denser. After the drum is struck, the air is set into motion, so its kinetic energy increases. The potential energy of the air decreases because the air is less dense.
Therefore, the air around the drum has more energy before it was struck.