Serpent
In this section
History
Serpent → ophicleide → euphonion → saxhorn → the modern horn: how the tenor voice of the low brass took its present shape in barely a century.
What was the ophicleide
A keyed brass bass instrument of the early 19th century — essentially a brass instrument with woodwind-style keys covering tone holes. It bridged the serpent and the valved euphonium and tuba, then was made obsolete by them.