340
7 The Amazing Diversity of Brass Instruments
the instrument itself to the final sound. Traditionally instrument makers will have
made a conscious decision in specifying D min , but will have followed convention,
experience and creativity in designing the bore shape which of which B is one
measure. Indeed, small adjustments to bore shape may have negligible effect on
the value of B but important effects on intonation.
The mechanics of the instrument—whether natural or with toneholes, slide or
valves, or played with a hand in the bell—limit the possibilities for bore profile.
The application of toneholes has been most successful with instruments which
have a bore which expands throughout, often loosely referred to as ‘conical’
instruments. Opening a tonehole effectively removes a section of the tube at the end
further from the mouthpiece from the sounding length, and a cone when truncated
remains a cone. Conversely, the application of slides has been most successful with
instruments which have a bore much of which is close to cylindrical. In order to
obtain a substantial chromatic compass from the 2nd natural note upwards, the
sliding parts have to add up to one-third of the minimum sounding length which
requires a substantial proportion of near-cylindrical sliding tube. The invention of
the valve opened up a wide range of possibilities for effective instruments, and many
types of instrument were created in the nineteenth century as makers exploited these
possibilities and introduced types such as the cornet and the tuba which had no prevalve equivalents. Not all points in the three-dimensional space defined by sounding
length (L), bore size (D min ) and brassiness potential (B) are occupied by recognised
instruments; indeed, some points may represent instruments which could be useful
but have not yet been invented.
In this chapter the values of L and B are given for the instruments with all
toneholes covered (in the case of finger-hole and keyed instruments), or the shortest
length (for slide and valved instruments). In most cases the latter is the length
giving the nominal pitch of the instrument. Obviously opening toneholes, moving a
trombone slide, or operating valves will give a different bore shape and thus change
the value of B to some extent. Strictly speaking, a chromatic instrument should be
represented by a series of points on a plane defined by constant D min in this threedimensional space, and it is apparent to players if not to audiences that the timbre
changes as hole coverings, slides and valves are changed. For an instrument to have
a clear identity, the variations in timbre between adjacent notes cannot be too great.
The increases in B when slides are extended or valves operated are small, however,
especially for the more ‘cylindrical’ instruments with high values of B, but are more
significant for ‘conical’ instruments where slides and valves introduce sections of
approximately cylindrical tubing.
7.2 The Different Kinds of Brass Instrument
It is a valid question whether the hundreds of nominally different instruments
really all respond to the player and sound differently. After discussing valved brass
instruments in some detail, Carse (1939) states provocatively:
7 The Amazing Diversity of Brass Instruments
the instrument itself to the final sound. Traditionally instrument makers will have
made a conscious decision in specifying D min , but will have followed convention,
experience and creativity in designing the bore shape which of which B is one
measure. Indeed, small adjustments to bore shape may have negligible effect on
the value of B but important effects on intonation.
The mechanics of the instrument—whether natural or with toneholes, slide or
valves, or played with a hand in the bell—limit the possibilities for bore profile.
The application of toneholes has been most successful with instruments which
have a bore which expands throughout, often loosely referred to as ‘conical’
instruments. Opening a tonehole effectively removes a section of the tube at the end
further from the mouthpiece from the sounding length, and a cone when truncated
remains a cone. Conversely, the application of slides has been most successful with
instruments which have a bore much of which is close to cylindrical. In order to
obtain a substantial chromatic compass from the 2nd natural note upwards, the
sliding parts have to add up to one-third of the minimum sounding length which
requires a substantial proportion of near-cylindrical sliding tube. The invention of
the valve opened up a wide range of possibilities for effective instruments, and many
types of instrument were created in the nineteenth century as makers exploited these
possibilities and introduced types such as the cornet and the tuba which had no prevalve equivalents. Not all points in the three-dimensional space defined by sounding
length (L), bore size (D min ) and brassiness potential (B) are occupied by recognised
instruments; indeed, some points may represent instruments which could be useful
but have not yet been invented.
In this chapter the values of L and B are given for the instruments with all
toneholes covered (in the case of finger-hole and keyed instruments), or the shortest
length (for slide and valved instruments). In most cases the latter is the length
giving the nominal pitch of the instrument. Obviously opening toneholes, moving a
trombone slide, or operating valves will give a different bore shape and thus change
the value of B to some extent. Strictly speaking, a chromatic instrument should be
represented by a series of points on a plane defined by constant D min in this threedimensional space, and it is apparent to players if not to audiences that the timbre
changes as hole coverings, slides and valves are changed. For an instrument to have
a clear identity, the variations in timbre between adjacent notes cannot be too great.
The increases in B when slides are extended or valves operated are small, however,
especially for the more ‘cylindrical’ instruments with high values of B, but are more
significant for ‘conical’ instruments where slides and valves introduce sections of
approximately cylindrical tubing.
7.2 The Different Kinds of Brass Instrument
It is a valid question whether the hundreds of nominally different instruments
really all respond to the player and sound differently. After discussing valved brass
instruments in some detail, Carse (1939) states provocatively: