The trombone is a unique instrument within the group of metals having a double U-shaped rod to change the sound's range produced.
The ancient trombone was very similar to modern and was called sacabuxa. Nowadays the trombone is one of the instruments in jazz groups, and is part of the symphony orchestra.
Sacabuxa (ancient trombone), built by Jean Schnitzer (Nuremberg), 1581
Watch the video below and learn more about trombone.