| {2 Trumpets I, II.) | |
| | |
4 Horns I, II, | 4 Horns I, II, III, IV. | 6 or 8 Horns I, II, |
III, IV. | | III, IV, V, |
| | VI, VII, VIII. |
| | |
3 Trombones. | 3 Trombones I, II, III. | 3 Trombones I, II, III. |
| | |
1 Tuba. | 1 Tuba[8]. | 1 Tuba. |
----------------------+-------------------------+-------------------------+

[Footnote 8: Of late years sometimes two tubas are employed, by
Glazounov for instance in his Finnish Fantasia. (Editor's note.)]

The directions are the same as in the preceding table for wood-wind.
It is evident that in all three classes the formation may vary as the
composer wishes. In music for the theatre or concert room page after
page may be written without the use of trumpets, trombones and tuba,
or some instrument may be introduced, temporarily as an _extra_. In
the above table I have given the most typical formations, and those
which are the most common at the present day.

_Note I._ Besides the instruments given above, Richard
Wagner used some others in _The Ring_, notably the quartet
of tenor and bass tubas, and a contrabass trombone.
Sometimes these additions weigh too heavily on the other
groups, and at other times they render the rest of the brass
ineffective. For this reason composers have doubtless
refrained from employing such instruments, and Wagner
himself did not include them in the score of _Parsifal_.
Some present-day composers (Richard Strauss, Scriabine)
write for as many as five trumpets.

_Note II._ From the middle of the 19th century onward the
natural brass disappeared from the orchestra, giving place
to valve instruments. In my second opera, _The May Night_ I
used natural horns and trumpets, changing the keys, and
writing the best notes "stopped"; this was purposely done
for practise.

Though far less flexible than the wood-wind, brass instruments
heighten the effect of other orchestral groups by their powerful
resonance. Trumpets, trombones, and tubas are about equal