Source of Timpani

- ティンパニの成り立ち 音域と音の合わせ方 ティンパニの音域はどれくらい？
-- https://www.yamaha.com/ja/musical_instrument_guide/timpani/structure/structure004.html
https://www.yamaha.com/ja/musical_instrument_guide/common/images/timpani/structure_p04_02.jpg