I have one B-flat cornet that consistently does not sound right when I trill between E and F on the staff. (open to first valve). It's a half-step trill so easy enough in general. I have other cornets and trumpets and it comes out fine.
On this one otherwise excellent horn, it's OK if I keep the trill slow but as I speed it up just sounds like a mishmash rather than a clean trill. I've tried different mouthpieces, adjusting the slides, I've even had the valves aligned to no avail. This horn also trills well on other notes, even between open to first valve; it's just between E and F that it does not sound clean.
I'm perfectly willing to believe it's me, but I just can't square that with the fact I have no problem with this trill on other horns.
Has anyone else had a similar issue or have thoughts?