Pitch change of the stopped French horn

• Published in: The Journal of the Acoustical Society of America 2024-03, Vol.155 (3_Supplement), p.A109-A109
• Main Author: Pyle, Robert
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/10.0026978

Composers sometimes ask for a form of muting on the French horn called “hand stopping,” where the player closes the bell with the heel to the right hand as completely as possible. This alters the timbre of the instrument and its pitch as well. Players are taught to compensate for the pitch change by transposing down a semitone on the F horn. Stopping thus appears to have raised the pitch of the F horn by a semitone. However, if the heel of the hand is gradually closed from its normal “open” position to full stopping while the horn is played, the pitch falls smoothly. So does hand stopping raise the pitch, or lower it? This has been the topic of sometimes heated discussion among hornplayers for perhaps 250 years. An experiment shows that both viewpoints can be considered correct. A mouthpiece was fitted with an earphone and a microphone so that the acoustical round-trip time through the horn can be determined from the response to a click emitted by the earphone. As the hand is closed, the round-trip time increases (“pitch falls”) but as the hand approaches full stopping, an earlier reflection appears and eventually dominates (“pitch rises”).