Mouthpiece lip-pressing force and its component minimum and margin forces during French horn playing

In brass instrument playing, mouthpiece force (MPF) contributes to sound production while preventing air leakage and assisting embouchure function. The MPF consists of a minimum force to produce sound and a margin force as a safety measure. This study investigated the effects of pitch and dynamics of the sound produced on the French horn on the MPF and those two force constituents. Eleven professional players played long F2, F3, F4, Bb4, and F5 tones at p, mf, and f using an MPF sensor-equipped mouthpiece (MP). The MPF increased significantly with pitch and dynamics, from an average of 5 N for F2 to 40 N for F5 at mf, with inter-player differences at F5 from 16 to 73 N. The minimum and margin forces also increased with pitch and dynamics, with a large inter-player variation. For all pitches and dynamics, the margin force as a percentage of MPF ranged from 35% to 57%, much larger than that reported in an earlier trumpet study. This relatively high margin setting is considered a French-horn playing strategy, ensuring airtightness against thin-rimmed MPs, assisting embouchure function by tightening the boundary of the lip vibration area with the rim, and may also help increase lip tension.