a'). If the conductor attempts to have his orchestra perform under
these conditions, disaster will surely overtake him, and he will not
only find his ears suffering tortures, but will be more than likely to
hear uncomplimentary remarks from the neighbors, and will be fortunate
indeed not to be ordered on to the next block or the next town by the
police force! The difficulty arises, of course, because the oboe,
English horn, clarinet, and other wood-wind instruments are built in a
certain fixed pitch, and since the length of the tube cannot be
altered, they must either play in the pitch intended or else not at
all. In the case of the clarinet and flute, the pitch can be altered a
very little by pulling out one of the joints slightly (the tube is
made in several sections) thus making the total length slightly
greater and the pitch correspondingly lower; but when this is done the
higher tones are very apt to be out of tune, and in general, if the
player has an instrument tuned in high pitch, he cannot play with an
ensemble group having low-pitched instruments, especially when the
piano supplies the fundamental harmony. In the case of the brass
instruments, a tuning slide is usually provided, and the same
instrument can therefore be utilized in either low or high pitch
combinations.[27]

[Footnote 27: "High pitch" is employed mostly in bands; the reason for
its use being that the wind instruments are much more brilliant when
tuned to the higher pitch. It is encouraging to be able to state,
however, that more and more instruments are being built in
"philharmonic pitch" (a' 440), and the conductor who is organizing a
band or orchestra is advised to see to it that all players who are
purchasing new instruments insist upon having them built in this
pitch.]

[Sidenote: TUNING]

The conductor of an amateur ensemble group will find it very greatly
to his advantage to be able to tune the various instruments, or at
least to help the players to do it accurately. This involves not
merely a mechanical knowledge of what to do to the instrument to
change its pitch, but, what is much more important, a very high degree
of pitch discrimination on the conductor's part. It is at this latter
point that assistance is most often necessary, and the conductor who
can tell his cornet player when he is just a shade high or low, and
can determine precisely when the violinist has his strings tuned to an
absolutely perfect fifth, will have far les