st compass is
extraordinarily powerful, but does not lend itself to more moderate
shades of expression. The small clarinet in its highest register is
more penetrating than the ordinary clarinet. The low and middle range
of the piccolo and small clarinet correspond to the same register in
the normal flute and clarinet, but the tone is so much weaker that it
is of little service in those regions. The double bassoon extends the
range of the ordinary bassoon in the low register. The characteristics
of the bassoon's low compass are still further accentuated in the
corresponding range of the double bassoon, but the middle and upper
registers of the latter are by no means so useful. The very deep notes
of the double bassoon are remarkably thick and dense in quality, very
powerful in _piano_ passages.

_Note._ Nowadays, when the limits of the orchestral scale
are considerably extended (up to the high _C_ of the 7th
octave, and down to the low _C_, 16 ft. contra octave), the
piccolo forms an indispensable constituent of the
wind-group; similarly, it is recognised that the double
bassoon is capable of supplying valuable assistance. The
small clarinet is rarely employed and only for colour
effects.

The English horn, or alto oboe (oboe in _F_) is similar in tone to the
ordinary oboe, the listless, dreamy quality of its timbre being sweet
in the extreme. In the low register it is fairly penetrating. The bass
clarinet, though strongly resembling the ordinary clarinet, is of
darker colour in the low register and lacks the silvery quality in the
upper notes; it is incapable of joyful expression. The bass flute is
an instrument seldom used even today; it possesses the same features
as the flute, but it is colder in colour, and crystalline in the
middle and high regions. These three particular instruments, apart
from extending the low registers of the instruments to which they
belong, have their own distinctive peculiarities of timbre, and are
often used in the orchestra, as solo instruments, clearly exposed.

_Note._ Of the six special instruments referred to above,
the piccolo and double bassoon were the first to be used in
the orchestra; the latter, however, was neglected after
Beethoven's death and did not reappear until towards the end
of the 19th century. The Eng. horn and bass clarinet were
employed initially during the first half of the same century