(Former oboist) You can absolutely adjust the tuning of a note with embouchure, and in a group context will do so all the time to make chords tune better.
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.
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.
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.)
wind instruments don't have fixed tuning. intonation allows you to bend notes enough to get the tuning you want. for a dramatic example of this, look at the clarinet solo at the beginning of rhapsody in blue.
The glissando at the opening of rhapsody in blue is not a counterexample to fixed tuning. It is a specific technique availed by having open holes under the fingers: by sliding the fingers slowly off the holes, and partially covering the holes, you can get a glissando effect. This same technique is used to create semitones.
Both of these are very difficult to do precisely, and come at a significant cost in the agility of the player. They are more equivalent to pitch bending on a guitar than adjusting tuning systems on a violin, which has almost no impact. Instruments with valves and hole covers, like bassoons, make techniques like this extremely difficult if not impossible.
However, the holes in the instrument are drilled at specific places along the length of the instrument corresponding to specific notes. This is what gives the instrument its tuning. Hole positions are calculated and drilled very precisely to make sure that the instrument is in tune. It is not accurate to say that these instruments do not have fixed tuning. The tuning is literally drilled into the body of the instrument.
Dude I've played clarinet for literally a decade (and a few years of saxophone). Anyone who's even a moderately talented amateur can bend notes enough to bend your note out of equal temperament. Sure you don't do this for anything fast, but if you have a longer chord this is a very common technique.
