Progressive Duets Vol 2 Trombone. is a comprehensive publication of twenty graded duets that have been arranged or composed by Larry Clark,drawing on his extensive experience as a school music teacher and a prominet composer/arranger to create a collection of duets that will be useful in a variety of performance situations. Playing duets is an excellent way for the students to build ensemble skills with a colleague or teacher. This collection is a welcome addition to the repertoire.