Rubank edition. Teachers have long turned to Rubank to fulfill the need for fun, educational first-year solo and ensemble music. VanderCook Progressive Duets can be played by any two equal brass instruments in treble clef, and includes: • 16-measure "starter" duets in each of several time signatures (4/4, 2/4, 3/4 and 6/8) • 26 medium-level duets of varying styles and tempos • 8 medium- to medium-advanced pieces appropriate for contest. A winner for any level player.