"There were some problems with some tactics, techniques and procedures, the way in which close air support was supposed to have been executed in this case, such that, at least with one of the aircraft involved, a B-1 bomber, that plane because of how it takes its bombing routes had to break away from positive I.D.

VOA: standard.2009.06.08

In this case, the basic column of air is twelve and a half feet long and there are something called "Partials" or the "Harmonic series" That happens in anything, on a string instrument or whatever, but on the horn it's very distinct and that's what makes the different notes.

像这样,基本空气柱有十二个,每个半英尺长,圆号能发出分音,或泛音列,弦乐器或是,其他别的乐器中都有,但在圆号上,效果相当不同,这就是它能奏出不同音符的原因

耶鲁公开课 - 聆听音乐课程节选

In this case, the basic column of air is twelve and a half feet long and there are something called "Partials" or the "Harmonic series" That happens in anything, on a string instrument or whatever, but on the horn it's very distinct and that's what makes the different notes.

像这样,基本空气柱有十二个,每个半英尺长,圆号能发出分音,或泛音列,弦乐器或是,其他别的乐器中都有,但在圆号上,效果相当不同,这就是它能奏出不同音符的原因

耶鲁公开课 - 聆听音乐课程节选