Dueling Fundamentals: Advanced Fundamental Exercises for Two Euphoniums by Alexander Lapins is appropriate for college through professional euphonium players. The Wiffle Waffle, The Hip Lip Flip Trip, Melodic Minor Mayhem, and Arban Freaks Out are just some of the fun—but make no mistake, also challenging!—duets included in Dueling Fundamentals for Euphoniums. This book consists of six chapters: Long Tones, Fingerbusters, Flexibility, Range, Scales, and Mixed Techniques. In each duet, both lines are challenging—there is no “student” line and no “teacher” line. Therefore this book works well for lessons or as an excellent tool for two friends or classmates looking to challenge themselves and each other.