Music tranposition

Here is the dog - thank goodness for Jess and the ability to get out...

As the only French Horn player in our local Jazz Band I need to transpose the music before I can play it. Jazz bands don't usually accommodate French Horns...years ago I used to be able to do it sight reading.

Not any more, I'm not so quick, so I bought some music software that allegedly make this easy.

However, because I only do it once every two years I have to re-learn what to do every time....So it's that time of year and I am re-learning...again...and I'm quite wanting to kick something at the moment..