This is a very broad topic that I have thought about at length over the years.
When I first purchased my own euphonium for my own amateur music making enjoyment around 2002 or so, the Besson/Sterling sound with Wick 4ALs coming out of the UK seemed quite different than the US service band approach with the Willsons and 51Ds/BB1s. To describe it from my perspective, the British sound was darker AND broader whereas the American approach tended to be brighter AND more focused. Both approaches thrived in their respective environments.
But I think there are signs that those historical differences, however any of us may describe them, may be fading. For one thing, especially over in Europe, there is much more variety in equipment choices compared to the past. Bessons are likely still in the majority, but Yamaha, Adams, Geneva, etc. are certainly making inroads. Many different mouthpiece choices now versus 20 or more years ago as well. There are 4 different lines of Wick Steven Mead mouthpieces alone, the latest designs being advertised as being more brilliant sounding. That coupled with Bessons no longer being made with the original tooling over in Germany, etc., there are bound to be some gradual changes in overall sound tendencies. Compared to Europe, the DC service bands still are very much dominated by the Willsons, a clear nod to the success of the legendary Brian Bowman, but whether that will continue in the future now that he has retired remains to be seen.
Joe Alessi recently commented that the differences in the global approaches to trombone playing appear to be narrowing over time, and he attributed this to the internet, Youtube, and numerous international visits by famous artists, and cross polination of international students in their respective studios. I think he is 100% correct, and I wouldn't foresee it being any different, eventually, with euphonium.
- Scott
Euphoniums: Dillon 967, Monzani MZEP-1150S, Dillon 1067 (kid’s horn)
Bass Trombones: Greenhoe GB5-3G, Getzen 1052FDR, JP232
King Jiggs P-bone