It is well known what a musical line is. Most musical instruments have a linear character. The pitch of the different instruments corresponds to the breadth of a line: violin, flute, and piccolo produce a very thin line, viola and clarinet a somewhat thicker one; and by way of the lower instruments, one arrives at broader and broader lines, right down to the lowest notes of double bass or tuba.
The scale of values from pianissimo to fortissimo can be expressed by increasing or decreasing intensity of line, or by its degree of lightness. The pressure of the hand upon the bow corresponds perfectly to the pressure of the hand upon the pencil.
Wassily Kandinsky, Point and Line to Plane, 1926, 617-18.
Edgar Meyer’s 1B for Violin, Cello & Double Bass
performed by Edgar Meyer, Yo-Yo Ma, and Mark O’Connor