How does a cylindrical bore differ from a conical bore in trumpet-type instruments?

In trumpet-type instruments, the primary difference between a cylindrical and a conical bore lies in the shape of the tubing and the resulting tonal characteristics.

• Cylindrical Bore: Trumpets typically feature a narrow cylindrical bore that remains constant for most of the tube's length before expanding in the final third and terminating in a small bell. This configuration, when paired with a shallow-cupped mouthpiece, favors the production of high partials and contributes to a bright tone.1
• Conical Bore: Instruments such as the cornet and various horns utilize expanding bores that widen throughout all or part of the tube's length, usually ending in a larger bell. When combined with a deep-cupped or funnel-shaped mouthpiece, this design favors low partials and produces a more mellow tone, making these instruments function most efficiently in a lower range.1

Both bore types, when equipped with a mouthpiece and a bell, allow for the production of the full harmonic series. While the bore shape significantly influences the instrument's timbre and technical capacity, both are fundamental configurations in the development of Western brass instruments.21