【Trombone Studies: with 2CDs】 McChesney, B. McChesney Jazz Etudes and Duets: Bass Clef Jazz Etudes and Duets Product Code: 1501751425 Publisher: Chesapeake Music I bought this five years ago, but it was too difficult, so I kept it on the bookshelf. CDs unopened. I haven't used it much, but it's not new, so thank you for your understanding.