Product Group: Violin ensemble. Contributor: Waterfield, Polly. Welcome to Polytekniks - a lively and original approach to aspects of violin technique. These versatile and entertaining easy duets present a variety of musical and technical challenges for the young player, from string-crossing, finger extensions to coping with unusual or tricky rhythms. Polytekniks may be used either by a teacher and pupil, or by two students at different stages of development.