Trombone bore optimization based on input impedance targets

Optimization methods based on input impedance target functions have been proposed for the design of brass musical instruments. Criteria for target functions in trombone bore optimization are discussed, drawing on experimental input impedance data from a variety of high-quality trombones of differing sizes. An "inharmonicity plot" is introduced and used to aid the interpretation of impedance curves. An efficient optimization technique is described and is shown to be capable of predicting bore changes which achieve specified modifications to the input impedance curve while maintaining a smoothly-flaring bell contour. Further work is required to clarify the relationship between input impedance targets and the preferences of professional players.