[SPBesui]

I hope this doesn’t come across as rude, but have you ever held a trumpet? Even if you’ve never played one, you can see they have adjustable tuning slides (a main one at the first bend, then a smaller one off each of the three valves). Maybe you’re thinking of a bugle? But any decent bugle player can bend notes up or down at least a little, probably to compensate for weather/temperature/etc.

[pclmulqdq]

I have held a trumpet, and an oboe, and every other instrument I cited here. Bending notes a little bit (which you can do on almost every instrument with varying amounts of effort) is not equivalent to playing in an unequal temperament.

[SPBesui]

My point was more about the tuning slides on a trumpet, and that it doesn’t have a “fixed tuning.” It’s almost like a trombone in a way: you can play any tone you want within a certain range by adjusting the slides.

(I do apologize if I came across poorly—I couldn’t think of another way to ask the question.)