(Phil) Shouldn't be too bad. One is expected to get that note on the 'bone (not too often) but the worst thing about it is reading it, being all in bass clef. The rule is that if it's in the stratosphere and on a space it's a C, otherwise it's a B (usually Bb). If it's a D the composer/arranger is not a trombone player. These high notes are far better played by trumpets and cornets anyway. Power to your embouchure. :-)

[Rosie] I used to feel the same when I played violin, and the music dropped off the bottom of the treble stave. I've never been fond of leger lines.

I always get annoyed when a composer writes a bottom B# for a cello. At first sight, this note appears not to be on the instrument.

[rab] It can't happen too often, can it?

(Darren) Although leger lines are part and parcel of trombone playing (especially 1st and 2nd trombones) I'm very glad they don't go into Tenor Clef which to me would make it unreadable instead of merely difficult. Treble Clef is never used because most 'bonists can't read that either unless like me they're also piano players.