An surprising amount of classical and even modern music was originally intended to be for practice or for tuning. I was just wondering how much was out there.
I'll give two examples:
Mozarts 12 variations on Baa, Baa Black Sheep (I don't feel like referencing his original title) was apparently a practice piece for his students.
Kansas' "Dust in the Wind" was based on the practice chord progressions that Livgren was practicing on. His wife insisted that there was a melody to be found in it.