Obsolete musical instruments

There are a great variety of other instruments that have been made that are no longer around. Here are some examples:

• Basset Horn: A single reed instrument that was often bent in a variety of shapes then sent through a soundbox
• Natural Horn: An earlier form of the French Horn which uses a series of tubing extensions which attach at the mouthpiece hole.
• Rackett: A double-reed instrument that sends the sound through a series of waves to deepen the sound.
• Saxhorn: Adolphe Sax developed both the woodwind saxophones, and an odd variety of brass instruments called the saxhorn, a member of the Aerophone family of instruments.
• Theremin: An electronic instrument that features two antennas, and is played by moving one's hands up and down and side-to-side.
• Valve Trombone: A trombone that uses valves, like a trumpet, to vary the pitch, but still makes the sound of a trombone.
• Slide Trumpet: Essentially the opposite of the aforementioned valve trombone.
• Viola da Gamba: An early form of the Violin, which features 6 or 7 strings instead of 4.
• Wagner Tuba: A four-valve brass instrument created by Richard Wagner, similar to the tuba, but built more in a manner similar to the French Horn.

There are a great many others, but this is just a start.