Tube geometry determines which partials resonate and so shapes timbre

Evidence

The trumpet is mostly cylindrical, the cornet includes a higher fraction of conical section, and the flugelhorn is more conical still. These variations change which partials are most strongly resonantly reinforced, and thus change the timbre (see chapter 24). — Eric J. Heller, Why You Hear What You Hear- An…, 1482

Categorization

• XREF: connects to: Resonator geometry shapes which harmonics appear in an instrument’s sound — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1228