The euphonium has an extensive range, comfortably from E2 to about D5 for intermediate players (using scientific pitch notation).
It is one of two formal systems for naming notes in a particular octave, the other being scientific pitch notation.
Guido d'Arezzo developed a system of pitch notation using lines and spaces.
It is also called C in scientific pitch notation (1046.502 Hz).
Later it became a popular pitch notation, using usually a movable "do" system.
Octaves are given in scientific pitch notation, with Middle C written as "C4".
While they are still note-octave systems, if they are called "scientific pitch notation", this is certainly an error.
One of William's innovations as a cantor and notator was an alphabetic pitch notation.
Each note is played at C4 (see scientific pitch notation).
The range specifications given below are based on the American scientific pitch notation.