One of my favorite solos of Rafael Mendez is Hejre Kati. It was the first of his solos for which I purchased the sheet music while in high school, and I also played it in later years with the Coast Guard Band. Here is my euphonium-piano performance of that piece from my recent recital at the University of Iowa:
https://youtu.be/XChFJCxbzqU

With only one rehearsal for the entire recital, we did not get all the tempos and interactions where I wanted them, but I think the piece comes off well. See what you think!