From reader sully7:

A dehumidifier will do wonders! Even a fan to move the air around will help. As for the smell here is a great solution! Its called Tea Tree Treasure. Go to a health food store and buy a small bottle of Tea Tree Oil (this is a natural fungicide). Mine cost $6.99. Put 2 tsp of the Tea Tree Oil and a quart of water into a spray bottle. Spray it into the smelly areas and all around the basement, but don't saturate them. The Tea Tree oil smell is very strong! but when it dissipates you will notice the musty smell is less. Spray again the next day. Afetr a few days of this the musty smell will be gone. Good luck!