The acoustical problems presented by the French horn in concert halls and recording studios are a constant source of frustration for the acoustician. The unique performance practices employed by the horn player (hand in the bell, pointing the bell to the back of the hall) create confusing and seemingly contradictory acoustical demands. In addition, the nonscientific language of the performer tends to force the acoustician to disregard the very real concerns and knowledge of the musicians. For example, horn players want a diffuse and ‘‘mellow’’ sound but insist on acoustical conditions that allow clear and precise ensemble playing. This paper will describe a solution to the chronic problems experienced by the French horn section of the Calgary Philharmonic Orchestra in the new Jack Singer Concert Hall. This solution was possible because the researcher (a professional horn player and mechanical engineer) was able to translate the concerns of the horn players into scientifically acceptable terms and use this information to direct the project.