It is very important to have control of the bow for a variety of timbres, even for the most traditional classical gig. The more contemporary the music, the more important it becomes.
One of the great pleasures of my life was in discovering that playing sul ponticello, if done with care, can duplicate that wonderful distorted sound Jimi Hendrix used for his version of the Star Spangled Banner. I try to keep that sound at my fingertips for sharing with my students.
The timbre that is most ignored by classical players, though, is pizzicato. Until a few years ago I really had two pizzicato timbres, not really very different from each other. During work with Bert Turetzky I started to think more about timbres and to extend that thought to my own pizzicato technique.
Like most teachers of beginning strings in classes, I usually spend several weeks playing melodies pizzicato. Most of my students, especially the youngest ones, are resistant to playing pizzicato. They think it is a beginner thing, an UN-authentic way of playing the instrument. WHY? Because when you see video of people playing violin, viola, cello or bass, they are bowing 95% of the time.
So I began including some listening (and video when possible) in the early classes to four particular pieces: the scherzo movement of Tchaikovsky’s 4th symphony; the 4th movement of Bartok’s 4th string quartet, Strauss’s “pizzicato polka” and Leroy Anderson’s “plink plank plunk.” These pieces have the strings putting down their bows and plating pizzicato throughout. This helps students change the way they think about playing. I get to tell them that they are in reality starting with some really advanced techniques, pizzicato and special effects.
What I want to find next is video (or audio) of Nicholas Walker. I heard him perform at ISB convention last year, a truly awesome unaccompanied version of “Come Together”—most if not all of it was pizzicato.
I would welcome other suggestions of pizzicato pieces for just bass or string orchestra.