Replace consumables based on wear and performance, not only the calendar

Strings, drum heads, felts, batteries and other consumables do not all age at the same rate.

Assess physical condition, performance, frequency of use and storage conditions. A corroded string, damaged head or battery showing abnormal signs should not remain in service merely because a scheduled date has not arrived.

When replacing a consumable, inspect the surrounding parts as well; it is often the easiest moment to spot dirt, wear or loosening.