立式钢琴击弦机
/ˈtaɪps ɒv sɪnˈəʊvɪəl ˈdʒɔɪnts/
n
English: upright piano action · 立式钢琴击弦机
释义：Combination of elements whereby energy applied to a key is transferred to the hammer, which in turn causes the strings to vibrate.
English: upright piano action · 立式钢琴击弦机