These other instruments are filling in these things at various spots to produce this aggregate of the chord.

这些不同的乐器在不同的点上聚合成了一个和弦。

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You can do it on other instruments but on a string instrument it's the difference.

很多乐器都能奏出颤音,但弦乐器上　这种揉弦产生的颤音是不一样的

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In other words, what--or the woodwinds-- what family of instruments is playing here and is Tchaikovsky using a motive or is he using a theme at the very beginning of this concerto?

或者是木管乐器,换句话说,这里演奏的是什么乐器,还有柴可夫斯基在这首协奏曲的开始部分,运用了动机还是主题

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