The Selected Studies for Trombone edited by Himie Voxman (1952, Rubank & Hal Leonard) is still one of the most widely used books in American brass teaching. The book picked existing brass etudes in 13 different keys. There was, and still is, a shortage of intermediate material in the more complex key signatures. The excellent Voxman book is a fine bargain, and is highly recommended.
These new Counterparts are printed separately as a “part book” to save space and page turns. Most American trombone students and their teachers own the Voxman book. The primary intent is for recreational duet playing and for help with key security, sight-reading, intonation, ensemble, style matching, confidence and independence. These duets should enhance the Voxman etudes with some interesting harmonies and other surprises