The horn obviously is a brass instrument and what makes the sound is a vibrating column of air.

显而易见的,圆号是个铜管乐器,它通过震动空气柱来发出声音

耶鲁公开课 - 聆听音乐课程节选

Then a brass instrument enters and what is the name of this brass instrument?

然后一个铜管乐器出现了,那么这个铜管乐器是什么

耶鲁公开课 - 聆听音乐课程节选

Now the instrument is--that is--playing is a low tuba, a low brass instrument.

现在在演奏的乐器,是低音号,一种低音铜管乐器

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So the brass instrument is the--is a--trumpet.

那么铜管乐器是小号

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