The contrabass trumpet is the lowest sounding member of the trumpet family, most closely related to the Bass trumpet. It is a specialty instrument, very rarely used except when the performer deems it necessary.
In 1967 while playing with the Los Angeles Philharmonic, Roger Bobo was looking for an instrument that would fit the sound he was imagining for ‘Conzonas’ by Gabrieli. Unhappy with the sound of the contrabass trombone he sought assistance from George Strucel. The pair worked together to put together a makeshift instrument that later became known as the contrabass trumpet. The bell and tubing were provided by Bach. The bell was that of a contrabass trombone while the rest of the instrument was made from scrap material found at a music exchange. The final cost of the project by Roger Bobo and George Strucel amounted to merely $125.
Though the first contrabass trumpet was made as a sort of improvisation, the instrument has been revised and remade. Many large scale instrument retailers still sell the contrabass trumpet, even though it is significantly less popular than other trumpet models. The bell of current models being sold is approximately 24.5 cm while the bell of a regular trumpet is approximately 10 cm-12 cm. The mouthpiece that was designed separately from the main project is similar to a tuba mouthpiece in size and diameter which is approximately 30mm, while regular trumpet mouthpieces which are approximately 15mm in diameter.