We ask ourselves what one can do to develop the playing technique "vibrato" well oneself, but also to teach it even better. There is little practical literature and suggestions for learning and continuously developing vibrato on the violin and viola. We know of no systematic structure that really takes into account all levels of performance, from preparation to professionalism.
Most important challenges
In the case of the high strings, a distinction is made between different types of vibrato: arm vibrato, wrist vibrato and finger vibrato. In addition to the prerequisite of sufficient mobility in the arm, wrist and fingers, there are two other important challenges:
The regulation and balancing of the finger pressure provides the necessary flexibility when vibrating. At the same time, good stability and flexibility of the finger on the string are required. The finger must be stable and flexible at the same time, otherwise there will be great intonation fluctuations. Being able to actively create this balance and constantly change it while vibrating is a prerequisite for consciously using vibrato.
The speed of the vibrato / the use of the vibrato in general, should also be consciously controlled in order to achieve the exact timbre one has in mind. To be able to do this consciously, one needs an increasing independence between the bow speed and the vibrato movements. If this independence does not exist, a faster bow stroke automatically causes a faster vibrato movement (and vice versa).