Comment by mbrameld
3 hours ago
Do you mainly control pitch with the tuning slide or the valves on those instruments? I think you mainly control pitch with the valves and only supplement with a tuning slide for certain notes, depending on the instrument, and therefore the statement is accurate.
Mainly the valves. The tuning slides help with a number of things, including the fact that the harmonics (notes above the first ocatave) are not precisely in tune with the fundamentals. A trumpet typically has a trigger lever or a loop for your finger on one or two of the tuning slides.
You use it as needed. If you're playing a really fast passage, you'll likely skip it, but shorter notes are harder to place the precise pitch anyway.
If you really want to see tuning slides in action, find a video of a good tuba soloist.
The slides are needed, at least on the trumpet, because the tuning is perfect when using one valve but it's way off when you use two at once.