Mike Saville said:Not sure about using vib on the bass trom to center notes . . . . :?
I have that one on good authority from Edward Kleinhammer and Doug Yeo - just a little vib though
However you are correct in that your sound needs to change for certain requirements. Take Coventry Vars for example. I have several moments where 1st trom needs to blend with solo cornet so I add some vib (& adjust my tuning!) accordingly. Much of the rest of the piece however requires a stright tone and a more 'orchestral' approach.
When I heard CV for the first time I was suprised at the 'orchestral' nature of the trom parts (much more use of brassy tone and dynamic variation) it is intresting to see brass band composers writing for larger bore orchestral instruments.