"The trombone is the only brass instrument in a classical orchestra" is a statement that requires further support.
It’s slightly confusingly phrased, but the full sentence is:
> The trombone is the only brass instrument in a classical orchestra […] where the main mode of pitch control is by moving the tuning slide.
Which is correct.
It’s slightly confusingly phrased, but the full sentence is:
> The trombone is the only brass instrument in a classical orchestra […] where the main mode of pitch control is by moving the tuning slide.
Which is correct.