The octave key is a key on a saxophone
which raises the pitch
of all notes by an octave
when pressed. It is positioned next to the left thumb. The presence of this
key is one of the main features which makes the saxophone easier to play than
the clarinet, because
the same fingerings can be used for two different octaves. The analogous key
on the clarinet, the register key raises the pitch by an interval of a twelfth
(19 semitones), making the fingerings different for low notes and high notes,
which are an octave apart.
