I've been playing around with just the bell section of the trombone ever since I was a kid. And then, I realized it had a very very unique sound, almost like an ancient instrument quality. I played it outdoors in Wales at an ancient Roman site and you could feel the battle that may have happened there, just from two notes. (You will hear these two notes in the beginning of the sound clip included below.)
Interestingly, in Wales, I started out by trying to play my trombone at that site and the sound didn't match what I was feeling there. So, I detached the slide from the bell and just played the part that I later named the T-horn.
Oddly enough, nobody has ever inquired about what a T-horn is, even though it's listed on the CD in the instrumentation. So, we think people assume T-horn is short for tenor horn, but now you know the rest of the story....
Here is a sound clip using T-horns: "Persian Immortals" from my "Occurrences" CD. It is also avaiable as a single track MP3 on the iTunes page for this CD.
By the way, this piece was written several years ago and was inspired by an ancient legend. It has no relationship to any current world events.