That's easy. There is a key sig in the middle of the screen. You didn't say what instrument you are playing. Just the key is displayed in the box, and it's a pull down box. I play the Bb horn and the G horn, and I know what I'm going to get without thinking about it, I just look at the range and pick a key. Actually most don't bother me, but if I'm going to switch from piano to horn in the middle something like F and G works as long as I don't have to whack off too many high C's. So if you are playing an Eflat horn it's +3 or -9. I'm not looking at the keyboard but if you have the song in E on an Eflat horn pull down the little menu and transpose to Ab. That should give you C on the Eb horn no? I then print out my part transposed, the wife's C part for flute, and another for the keyboard and Bob's yer uncle.

John Conley
Musica est vita