saxhorn. Type of brass wind instr. of wide semiconical bore, using cup mouthpiece and played with valves, invented by A. Sax c.1845. There are 7 varieties (deep bass to high treble), i.e. 2 sop., alto, ten., B♭ bass, E♭ bass, and BB♭ bass (BB signifies wider bore). They are transposing instrs.: those used in Brit. brass bands are the E♭ ten. (ten. hn.) and B♭ bar. (bar. hn.), both closely related to the Flügelhorn. Nomenclature for the group is somewhat confused, e.g. in the 4 higher instrs.:

(a) sopranino saxhorn in E♭ (or F), also called sop. saxhorn or (mistakenly) sop. Flügelhorn, or Flügelhorn piccolo. Little different from E♭ cornet.(b) sop. saxhorn in B♭ (or C), also called alto saxhorn or (mistakenly) alto Flügelhorn. Little different from B♭ cornet.(c) alto saxhorn in E♭ (or F), also called saxhorn, or ten. saxhorn, or ten. hn., or alto, or althorn in E♭ (or F).(d) ten. in B♭ (or C), also called bar., or bar. saxhorn, or althorn in B♭.

The 3 lower saxhorns are whole-tube instrs., the 4 higher are half-tube instrs. The 3 lower instrs. are classified with tubas, e.g.(e) bass saxhorn in B♭ (or C), almost identical with euphonium.(f) bass saxhorn in E♭ (or F), almost identical with E♭ bass tuba, otherwise E♭ bombardon.(g) double-bass saxhorn in B♭ (or C), almost identical with B♭ bass tuba but with complete range at bottom.

These are not always used as transposing instr.: sometimes the bass clef is used, sometimes the treble clef showing the notes an octave higher than if the bass clef had been used. In each case, middle C represents the octave of the fundamental note.

saxhorn brass musical instrument. XIX. f. name of Charles Joseph Sax (1791–1865) + HORN.
So saxophone, invented about 1840 by his son Antoine Joseph, known as Adolphe; see -O-.