The slide trumpet is an early type of trumpet fitted with a movable section of telescopic tubing, similar to the slide of a trombone. Eventually, the slide trumpet evolved into the sackbut, which evolved into the modern-day trombone. The key difference between these two instruments is that the slide trumpet possesses only a single slide joint, rather than the two joints in the U-shaped slide of the sackbut or trombone. There are several types of slide trumpet of different places and eras.