For the most part, embouchure (I think this is the right way to spell it) really only affects the instrument's tone, by which I mean both the tendancy to go sharp or flat while holding a note as well as the quality of the sound (ie EES IT PREETY??!@). It only affects range in the extreme cases. For example, go listen to some of the high notes that trumpet players like Maynard Ferguson and Arturo Sanduval can hit. Arturo hits fucking piccolo notes. Those guys have been playing for like 40 years and their embouchures are so tight and well-honed that they can create a buzz high enough to reach those octaves.
But what I was talking about was the valve combinations used to make each note. Like on a three valve instrument, the first two valves are what makes an "A" whether you're on a horn, trumpet, bari, tuba, etc.
