To purchase the viola version of the Exercises for Change of Position, visit Amazon.com
If you are looking for one of the Yost System's original books for the violin, please visit the Yost Family Trust website, where you can find information about G. Yost's works and purchase his books.
If you are looking for one of the Yost System's original books for the violin, please visit the Yost Family Trust website, where you can find information about G. Yost's works and purchase his books.