With all the changes that have come over the orchestra in the course
of the last two hundred years, the string quartet has remained its
chief factor. Its voice cannot grow monotonous or cloying, for,
besides its innate qualities, it commands a more varied manner of
expression than all the other instruments combined. The viol, which
term I shall use generically to indicate all the instruments of the
quartet, is the only instrument in the band, except the harp, that can
play harmony as well as melody. Its range is the most extensive; it is
more responsive to changes in manipulation; it is endowed more richly
than any other instrument with varieties of timbre; it has an
incomparable facility of execution, and answers more quickly and more
eloquently than any of its companions to the feelings of the player. A
great advantage which the viol possesses over wind instruments is
that, not being dependent on the breath of the player, there is
practically no limit to its ability to sustain tones. It is because
of this long list of good qualities that it is relied on to provide
the staff of life to instrumental music. The strings as commonly used
show four members of the viol family, distinguished among themselves
by their size, and the quality in the changes of tone which grows out
of the differences in size. The violins (Appendix, Plate I.) are the
smallest members of the family. Historically they are the culmination
of a development toward diminutiveness, for in their early days viols
were larger than they are now. When the violin of to-day entered the
orchestra (in the score of Monteverde's opera "Orfeo") it was
specifically described as a "little French violin." Its voice, Berlioz
says, is the "true female voice of the orchestra." Generally the
violin part of an orchestral score is two-voiced, but the two groups
may be split into a great number. In one passage in "Tristan und
Isolde" Wagner divides his first and second violins into sixteen
groups. Such divisions, especially in the higher regions, are