Hmm...My Edit button won't appear to edit my above post, so I'll have to make a new post to say this.
Either the Rose theme, or....
Song For Ten. But I'm talking about the piano/orchestral version used at the end of School Reunion. It's hard to pick out, but as long as you have the tune worked out from The Christmas Invasion you can then add the version from the beginning of Army of Ghosts which is the same as from School Reunion but without the piano and more of an orchestra. Sorry if I'm not making much sense, I'm in a bit of a hurry right now. Sorry!
Hope you take note of this Danny and I look forward to listening to more of your incidental work!