Say you have a piece of music written for French Horn in F. Now, this piece has to be transposed, or played directly off the sheet music, on Alto Saxophone in Eb.
And here’s the thing: When the original key is A-major for the Horn in F, which key the Alto in Eb is playing?
Mine (and other’s - luckily) first reaction was to say a whole-step down, ie G-Major, since the Frensh Horning tuning is F and the other Eb, when in fact it is a whole-step up, therefore B-Major.
When the horn reads “A” it actually sounds “D”, which would be “B” on the alto. Figured this out during the first lesson of this day, which was a confusing way to start the day.