Wolf tone attack!

If you play cello you probably have experienced the undesirable and sometimes unbearable effects of a distorted resonance that is called a wolf tone. Cellos seem to be particularly prone to wolf tone problems but they can affect violins and violas as well.

The causes of wolf tones have been debated for centuries. Here is a summary of one of the theories.

Every cello has a fundamental pitch; the pitch at which the air cavity resonates most fully. When you play that pitch especially in the lower register usually between E-F# you will notice a pronounced louder and “thick” tone. The wolf is not usually such a problem on C string, the problem note is usually on the D string between E-F# and will be worse at the same pitch on the G string. The problem is created by the fact that the fundamental tone of the cello is usually the same as the tone the top and the back generate when vibrating. This creates a sustaining sympathetic artificial overtone that amplifies and expands the frequencies of the original note, frequently accompanied by an oscillating beating due to the uneven frequencies between the natural note and artificial overtone.