The four movements of the left hand fingers necessary for string playing (to paraphrase the great violin pedagogue Demetrius Constantine Dounis) are:
- Lifting: Raising a finger from the fingerboard/string
- Dropping: Lowering a finger/Pressing a string to the fingerboard
- Sliding: Moving a finger along the string so the pitch rises or lowers accordingly
- Holding: leaving a finger down on the string
Executing any one of these movements is quite easy for most people. To hold down a note with second finger, for example, is manageable by most beginners. Compelling two separate fingers to perform two different motions, however, can be a challenge. However, it is worthwhile to attempt, as our ease of play will increase as the independence of our fingers increases.
I like the simple exercise below as an initial step towards finger independence. The concept is simple. We will Hold a note with one finger while Lifting with another. Specifically we will bow a scale in whole notes (Holding) while we pizzicato with a different left hand finger in quarter notes (Lifting). Notated, it might look something like this:
The fingering given above is not essential. So long as you abide by the concept of Holding a note with one finger and Lifting (i.e. left hand pizzicato) with another you will gain benefit. For those who are ambitious, try every possible finger combination.
Work on this exercise daily until you can perform it rhythmically, with minimal tension in your left hand and with a good tone on both the bowed notes and pizzicato notes. Mastering this exercise may require some time, but the benefits for your stamina and ease of play will be numerous.