Editing Timpani (section)

=== Heads ===
Like most [[drumhead]]s, timpani heads can be made from two materials: animal [[skin]] (typically [[calfskin]] or [[goatskin (material)|goatskin]])<ref name=grove/> or [[plastic]] (typically [[PET film (biaxially oriented)|PET film]]). Plastic heads are durable, weather-resistant, and relatively inexpensive. Thus, they are more commonly used than skin heads. However, many professional timpanists prefer skin heads because they produce a "warmer" [[timbre]]. Timpani heads are determined based on the size of the head, not the bowl. For example, a {{convert|23|in|cm|adj=on}} drum may require a {{convert|25|in|cm|adj=on}} head. This {{convert|2|in|cm|0|adj=on}} size difference has been standardized by most timpani manufacturers since 1978.<ref>[http://www.steveweissmusic.com/product/timpani_head_size/articles "Timpani Head Guide"], ''Steve Weiss Music''</ref>