Skilled saxophonists and clarinetists have to minutely coordinate their fingers with the tongue actions and the air pressure in order to produce every nuance of expression with utmost precision expected from professional music performances nowadays. The fingers press down and release multiple tone-holes and keys to allow or prevent air from streaming out and thus change the pitch of the tone. While the fingers mainly control pitch, the tongue controls many other expressive parameters such as onset and offset timing and articulation (connection of successive tones).
This research project measured and studied the above mentioned aspects of performances on single-reed woodwind instruments such as the saxophone and the clarinet: finger forces were monitored during playing with instruments equipped with custom-tailored force sensors at the tone-holes while a bending sensor, placed directly on the reed, registered the vibrations of the reed and tongue actions to it. The prototype instruments were a sensor-equipped saxophone and a specially engineered sensor clarinet, both designed to allow completely “natural” performances like playing on normal, unequipped instruments.
The force sensors for the clarinet prototype were developed, built, and tested during this project to exactly fit the geometry of the clarinet key-work. For the set-up of the sensors, Low Temperature Co-fired Ceramic (LTCC) technology was used. LTCC technology shows excellent prerequisites to fabricate the sensor element together with its packaging in a customized way. This is especially important for the different dimensions and shapes of the tone-holes and keys of the clarinet.
Student-level and professional saxophonists and clarinetists were invited to perform on these sensor instruments in separate carefully controlled experimental situations while their finger force profiles and the reed signals were recorded together with the sound of the saxophone and the clarinet, respectively. These experiments addressed whether different effectors (the tongue, the fingers, or the both combined) produce different degrees of timing precision at a range of performance tempi (slow, medium, fast), whether finger forces applied to the clarinet keys change with performer skill (professionals pressed less than students), performance tempo (clarinetists press less when playing at fast tempi), or the musical material (clarinetists press more when playing expressive music than in finger exercises).
The sensor system developed here may be adapted in the future to be built into other instruments, such as the bassoon, the oboe, or even the piano. The methodological foundations for capturing and analyzing finger force profiles laid within this project may be expanded to intelligent real-time feedback systems applied in music education.