Edwards Bass Trombone Tuning SlideTuning slides are available in yellow brass or rose brass. We have found that most people prefer offsetting the bell with the tuning slide yellow bell with rose tuning slide or red rose bell with yellow tuning slide. Single Radius tuning slides are the most common. They have one continuous bend from small to large end. They are very free blowing and open in all registers. Dual Radius tuning slides have two bends. The shape is more square with the two