For all of my life I have been disappointed with standard key studies. They are usually scales or parts of scales and often they leave out what they consider to be difficult keys.
Great so everybody can play in the key of C, F, G most in Bb and D then we start losing people and by Db we have lost 95% of players and by F# oh well.
This problem happened to us because most people did what Arban did. The Arban key studies had 15 exercises for C major and 1 for F#. As the keys got more sharps and flats he had fewer exercises.
We won’t practice what we don’t have.
So in my New Arban every key had 24 exercises.
But still they weren’t songs.
I used these 2 Concertos The Haydn and The Hummel with my students but I never had them in a key study book. Each Concerto is written 24 times and covers every key. I even do the B Cb, C# Db and F# Gb combinations.
These are great songs and work the keys extremely well. Plus as an added benefit I kept going so that we had great music to work range with. So this book covers a LOT of playing issues at once.
The Haydn and Hummel Trumpet Concerto Key and Range Study Ebook is 485 pages and covers the concertos in every key.