This may sound like a really really silly question, but here goes.

I'm trying to transpose Sibelius' Symphony No. 1, Op 39 for Trumpet. It's for an orchestral summer school i am attending in less than two weeks... But I need a bit of closure with the last movement.

The first three movements (1. Andante, ma non troppo 2. Andante, (ma non troppo lento) 3. Scherzo: Allegro) in the part I am transposing for are written for Trumpet in F, but the last movement (4. Finale, quasi una Fantasia) is written in something else, NOT F, but I can't make out clearly what it says at the start of the movement. It appears to be either a C or an E, definately doesn't look like an F.

Can anyone help me out?

Not a silly question at all, sometimes those old parts are barely legible. You could play along with a recording, using different transpositions until you find the right one.

Looking at the score, the Finale appears to be written for three Trumpets in E. Your transposing job just got a lot easier.

Fantastic! Thankyou so much.. now to work out how to transpose E - Bb

How incredibly cool! I know what I'll be listening to tonight.

Just remember that the trumpet in E sounds a major third above written pitch, and the B-flat sounds a major second below it... so you need transpose all the written notes upward by maj3rd + maj2nd = diminished 5th.

In the score, the key signature for the trumpet part is in C, but remember it will transpose up to E. The B-flat will need to transpose its written part DOWN to E, so you'll need to write it in G-flat. Change the key signature, then just move all the notes up a fifth.

(Note: the above kind of makes the assumption of major key here, but even if it's written in the relative minor, the process is exactly the same.)

Of course, all this makes me wonder why they don't just write the notes that the instrument actually sounds, rather than all this transposing....