Measurement Techniques and the Playability of Terminal Horn Crooks

Before the invention of valves, orchestral horns were generally equipped with a number of crooks of differing effective lengths to facilitate the use of the instrument in music of different tonalities. Even after the introduction of valves, some horns continued to be provided with detachable crooks. The experience of players is that the choice of crook critically affects the response of a horn, and that different crooks providing the same nominal pitch can have appreciably different playing properties. The bore profiles of a sizeable sample of terminally-fitting crooks with effective lengths up to 3.5m were derived from wide-band input impedance measurements using a multiple microphone technique. Bore profiles were also derived from time domain pulse reflectometry measurements for comparison. The correspondence between the bore profile of a crook and the intonation and ease of note initiation when played by appropriately experienced horn players was explored in a series of playing tests.