Contrabass trombone - Brief description

Contrabass trombone in F
German: Kontrabassposaune in F
French: trombone contrebasse
Italian: trombone contrabbasso in Fa
The modern contrabass trombone is a slide trombone tuned to the fundamental of F1 with two valves, which are activated by the thumb of the left hand and make it possible to lower the instrument’s pitch from F1 to Eb1 or Bb0 while playing. Opening both valves simultaneously puts the instrument in Ab0. The contrabass trombone is used principally for the great octave and the contraoctave.
Classification
Aerophone, brass wind instrument
Material
Mainly brass, often gold brass; nickel silver
Mouthpiece
Cup-shaped mouthpiece, a little larger than that of the tenor trombone
Tubing
Length approx. 370 cm, cylindrical, conical at the bell
Bore
Narrow, a little wider than the bass trombone
Valves
Two valves (Eb and Bb), Ab crook (whole-tone crook)
Bell
Rim diameter approx. 29–30 cm