Here is a backing track and demonstration video for the ‘pizzicato open strings’ exercise on page 13 of Violinworks Book 1. If you find this exercise too quick, try playing along to the ‘slowed-down drum groove’ backing below, or play along to your metronome (crotcher=c.8. For sheet music, CD performance tracks and many more exercises and pieces, order a copy of Violinworks here.
Backing track (4/4 drum groove):
Slowed-down backing track (4/4 drum groove):