I've got two horns which I regularly practice, an old German small bore "kozertposaune" type of horn, and a modern large bore.
On both horn I use mouthpieces, with size 4 rim sizes, a Schmidt Bambula 4 1/2 for the German horn and a Hammond 11ML for the large bore.
On the German horn, I've got a high range up to
, including a good sounding high e natural, which I've never been able to achieve on any other horn I've tried. On the large bore, I've got a reasonably consistent high e flat, and occasionally a high f, but almost never a high e natural of any quality.Unless, and here comes the interesting bit, I've been practicing the German horn for a couple of days, and then return to the large bore instrument, in which case the range all the way up to the high f, including that pesky high e natural is present, but only for the first practice session on the large bore. After a day it falls back down to high e flat, never to return back up, until I play the German horn again.
Any ideas what is going on here?
. It's weird. No amount of experimentation has brought me any closer to hitting those two pitches as cleanly as the high C, D or F+. 