Although you can build a left-handed trumpet, left-handed players I know just play a regular one and use their right hand on the valves. My pro lefty brother did it that way.

In school, sometimes a trumpet player will be asked to switch to French horn, where the valves are played with the left hand. For some reason, this switch doesn’t seem to be difficult.

Not only can I play French horn well enough, but I discovered I can finger scales quite well with the left. I did this when my right hand was mildly injured and I just played a concert with my left. I don’t understand why but muscle memory from decades of scale drills seems to have carried over to the other hand. Apparently the brain can make that switch. At least it works for me.

As Notes said, sax requires a good left hand far more than a right hand. Flute, also, to a lesser degree.

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