If they are not washable, spray your clothing with a commercial odor stopping spray, such as Febreeze. If you can wash them, add a cup of vinegar to the washing, the vinegar smell will wash out along with the musty smell.
The best way to air them out would be to hang them outdoors if the weather in your area permits. Otherwise, you may have to wash them multiple times to get the odor out. Be sure to either dry them in a dryer or hang them to dry in a well-ventilated, dry place.