Predicting the playing frequencies of brass instruments

The frequency of a note played on a brass wind musical instrument is usually close to the frequency of one of the peaks in the input impedance curve of the instrument. The exact playing frequency also depends on factors, including lip tension and vocal tract shape, which allow an experienced player to modify the pitch and timbre of a note without changing the physical shape of the instrument in any way. This ability to ‘bend’ or ‘lip’ a note is useful in making subtle adjustments of intonation, and in creating a musically expressive performance. This paper presents studies of the sounding frequencies of notes played on brass instruments using both human players and an artificial mouth. The extent to which the playing frequency can deviate from the acoustic resonance frequency is studied for different playing regimes, and the results are compared with numerical predictions using a lip model with two degrees of freedom.