Chris Gekker’s famous 44 Duos for Trumpet. Let’s see what Chris has to say about the purpose of the book, here is an excerpt from his forward:
These duos are intentionally short; the idea is for the two players to practice matching and blending while staying fresh. I have tried to cover a wide variety of challenges regarding intonation, rhythm and key signatures. Feel free to alter note shapes, styles of articulation, dynamics and tempi.
To address certain rhythmic problems, I have borrowed ideas from various composers, including JS Bach, Igor Stravinsky, Samuel Barber, Maurice Durufle, and Alec Wilder.