Mr. Vernon believes it is important for tenor trombonists to maintain this vulnerable register on a daily basis. Second trombone and bass trombone players constantly play in this register in ensembles. Tenor trombonists who don't work in the middle/low register will have many difficulties playing these studies. This register is a primary building block to producing a free, open and easy sound over the entire range of the instrument. 59 pages. 659550951043.