Basic Instrumental Fingering Chart Trombone Is ideal for every beginner, Ideal for any private student, classroom study or for quick and easy reference while practicing at home. The chart includes diagrams of major scales, minor scales, trills & the circle of fifths which is essential in learning how to determine the key signature. Learning the keys is an imperative element of music study for every student and the sole reason we chose to place so much emphasis on the "Circle Of Fifths" diagram.