tremulousness of tone akin to the _vibrato_ of a singer; and, like the
vocal _vibrato_, when not carried to excess, this effect is a potent
expression of sentimental feeling. But it is much abused by solo
players. Another modification of tone is caused by placing a tiny
instrument called a sordino, or mute, upon the bridge. This clamps
the bridge, makes it heavier, and checks the vibrations, so that the
tone is muted or muffled, and at times sounds mysterious.

[Sidenote: _Pizzicato on the basses._]

[Sidenote: _Tremolo._]

These devices, though as a rule they have their maximum of
effectiveness in the violins, are possible also on the violas,
violoncellos, and double-basses, which, as I have already intimated,
are but violins of a larger growth. The _pizzicato_ is, indeed,
oftenest heard from the double-basses, where it has a much greater
eloquence than on the violins. In music of a sombre cast, the short,
deep tones given out by the plucked strings of the contra-bass
sometimes have the awfulness of gigantic heart-throbs. The difficulty
of producing the other effects grows with the increase of difficulty
in handling the instruments, this being due to the growing thickness
of the strings and the wideness of the points at which they must be
stopped. One effect peculiar to them all--the most used of all
effects, indeed, in dramatic music--is the _tremolo_, produced by
dividing a tone into many quickly reiterated short tones by a rapid
motion of the bow. This device came into use with one of the earliest
pieces of dramatic music. It is two centuries old, and was first used
to help in the musical delineation of a combat. With scarcely an
exception, the varied means which I have described can be detected by