diapason  
noun uk/ˌdaɪ.əˈpeɪ.zən/ us/ˌdaɪ.əˈpeɪ.zən/
  (MUSIC)              
  [ C ] music specialized (管风琴的)主音栓
one of two main stops (= sets of pipes) of a pipe organ
  The pipes play with open, stopped, and double diapason. 管风琴通过开管、闭管和低音主音栓演奏。 
 One of the largest and most fundamental diapasons, or sets of pipes, was given away. 最大、最重要的主音栓之一便显露出来。 
  [ C ] music specialized (管风琴等)陡然变强的乐音
a musical sound that suddenly gets louder, like the sound of an organ
  The hymn rose in a swelling diapason. 随着陡然而起的强音,圣歌也越来越嘹亮。 
  [ C ] music specialized 旋律,曲调
the range of sounds or notes made by something
  Each trickle contributes its tiny warble to the diapason of the waterfall. 每一条涓涓细流都为瀑布的旋律贡献着自己微小的莺声燕语。 
  [ C ] music specialized 音叉(同 tuning fork)
a  tuning fork 
 - More examples
 - This organ incorporates parts of the original organ and also a pedal open diapason given as a gift to the church.
 - The organ swelled in a muted diapason, soon dropping to an almost inaudible tone.
 - The shattering symphonies or dying murmurs of the organ suggested the rushing of the wind through the forest, then the full diapason of the storm.
 - The forks are tuned to a Diapason normal, also called low pitch or French pitch.
 
  (RANGE)      
 [ S ] literary(活动、情绪等的)范围,领域 
the full range of something
  We can't quite find it in our hearts to sound the diapason of our disgust at what he has done. 我们实在不忍心充分表达对他所作所为的厌恶之情。