A mechanical device for altering the basic tube length of a brass instrument by a predetermined and fixed amount while it is being played.
3. Compensating and key-changing valves.
PHILIP BATE/EDWARD H. TARR
It is a useful, if not strictly accurate, convention to call the lowest vibration frequency theoretically possible in a given air column (mainly governed by its length) the ‘fundamental’, and its overtones ‘harmonics’ (the fundamental and the harmonics being referred to collectively as ‘partials’), even if they do not quite form a mathematically true harmonic series (for a stricter definition of these terms See Sound, §5(ii)). Ex.1 shows, up to the 16th partial, the notes theoretically obtainable from an 8' tube, and the portions of the series used for musical purposes on three types of simple or unmechanized brass instrument. Partials 7, 11, 13 and 14 are out of tune with the equal-tempered scale. (For a discussion of the resonance properties of air columns, see Acoustics, §IV). Although some skilled players can extend the upper range by eight or more harmonics, such a sequence clearly has little potential in music based on the chromatic scale. If, however, the air column is lengthened by an appropriate amount, a new fundamental and its attendant series of harmonics will be introduced. The valve accomplishes this by, in effect, introducing extra lengths of tubing. Three valves – to lower the fundamental of the primary tube by a semitone, a whole tone and three semitones respectively – when used singly and in combination make available seven different fundamentals. Ex.2 shows how the player can command a chromatic scale with a selection of harmonics from the seven corresponding series. The sounds under 1 are fundamentals. Partials 7, 11, 13 and 14 have been omitted as they are out of tune with the equal-tempered scale and are not used by valved instruments; 15 is seldom used in practice, though the note is a good one. The lines with arrows show the fingering. The void notes between partials 5 and 16 are used only occasionally, for convenience in fingering, since the equivalent sounds can usually be better tuned with standard fingering.
In most brass instruments of fairly narrow bore (trumpets, cornets etc.) the fundamental is not usually playable and the useful scale begins on the 2nd partial, an octave above. In wide-bore instruments (e.g. tubas) the fundamental is a valuable note; three valves, however, are not sufficient to connect it chromatically with its octave. A fourth valve, bringing in additional tubing to lower the pitch of the instrument five semitones, fills the gap when combined with the basic three valves in different ways and thus renders the instrument fully chromatic from the fundamental upwards. An inherent defect in any additive valve system, however, is that a supplementary tube designed to lower the pitch of an instrument by a given amount will be too short to do this if the main tube has already been lengthened by another supplement. Thus notes requiring the use of two or more valves together tend to be sharp – as much as a semitone in some instances where all three essential valves are combined. On small instruments the player can usually ‘pull’ or ‘lip’ the defective notes into tune, but on the larger ones this is hardly possible; consequently, on a tuba, a fifth or even sixth valve may be added to improve intonation. The extra valves are arranged differently by different makers, or according to the ideas of particular players; in six-valve instruments the commonest arrangement is for the fourth and sixth valves to supply a perfect 4th and perfect 5th respectively. The fifth valve is then tuned to an approximate semitone which can be used to fill in deficiencies elsewhere.
The ‘ascending third valve’ was until recently favoured by many orchestral and solo horn players, especially in France. In this system the third valve, instead of adding a supplementary section, cuts out a section of the main tube, thus raising the pitch of the instrument. An ‘independent’ valve system introduced by Sax of Paris in 1852 comprised six valves, each of which added its own complete length of supplementary tubing to lower the fundamental by a semitone more than the preceding length. Thus, using the open note and then each valve in turn, the player could command seven different harmonic series. As applied to the trombone this system had some success, but the weight of the necessary tubing and the generally unfamiliar fingering led to its ultimate disappearance.
Three types of valve are in use today – the piston valve (Fr. piston; Ger. Pump(en)ventil, Périnet-Ventil; It. pistone), the rotary valve (Fr. cylindre rotatif; Ger. Drehventil, Zylinderventil; It. cilindro rotativo) and the double piston or Vienna valve (Fr. piston double; Ger. Wiener Ventil). The first two are used by most brass players and appear to be equally favoured. The Vienna valve (Ger. Wiener Ventil) is employed today only on horns, and only in the area around Vienna. According to Pierre, 1890, a related version was once very popular with Belgian instrument makers to the extent that it was called système belge.
The piston valve consists of a cylindrical outer casing of brass and the piston or ‘pump’. The latter is a cylinder of thin sheet metal ground into the casing with abrasives so as to be as airtight as possible while able to move freely. It is held at rest in the ‘up’ position by a spring, either above or below it (the latter is cheaper), according to the preference of the maker. Frequently it is made of, or plated with, some metal of low friction when opposed to brass. The casing is perforated to correspond with the main tubing of the instrument and has elbows leading to the supplementary tubing or ‘valve slide’, which is telescopic and may be pushed in or out for tuning purposes or withdrawn entirely to drain off the moisture that condenses during playing. The structure and interconnection of a normal cluster of three valve cases is shown in fig.1. The wall of the piston is also perforated and is fitted with three transverse tubes so placed that when the piston is in the up position one of these provides a direct passage through the valve, and when it is down the others divert the windway through the supplementary tubing, thus adding its length to the main tubing of the instrument (see fig.2).
The rotary valve also has an outer casing perforated to accommodate the main and supplementary tubing, but the perforations are all in the same plane, placed at four points equidistant from each other. Two tangential passages are arranged so that when the inner part, or rotor, is at rest there is a clear passage through the valve. A quarter-turn of the rotor diverts the windway through the valve slide, which is essentially similar to that of a piston valve (see fig.3). (The rotor may be turned from solid metal or may be built up from sheet.)
Complications arise, however, in converting a downward finger pressure into rotational movement. Thus various return mechanisms have been devised. The earliest non-tubular valves (Ger. Federstecher; first developed in Leipzig in 1821) were activated by a rod around which a spring was wound, both of these elements being enclosed in a short casing otherwise much resembling that of the modern piston valve. Josef Kail’s Vienna valves of 1823 were activated by touchpieces attached to long flat springs, a system which was subsequently employed by C.A. Müller of Mainz (first working for Schott and then on his own). In his patent of 1830 Leopold Uhlmann displayed a type of clockspring in a separate casing anchored to a fixed axle (placed at some convenient point on the instrument) and to the inside of its own casing. To the outside of this is attached the touchpiece, which remains up at rest. The touchpiece is linked to the rotor by a crank and a connecting rod, so that pushing down on it causes the rod to rotate as far as two buffered ‘stops’ will allow, at the same time winding up the spring a little. With the release of pressure the spring reverses the movement (see fig.4). When well made this mechanism proves entirely satisfactory, but it is somewhat prone to wear and inadvertent damage.
A mechanism (Ger. Spiralfederdruckwerk) developed in the 1840s eliminated the clock spring and casing. Here the touchpiece is kept at rest by a simple spiral spring wound round its axle. A further development was the ‘American string action’ (Ger. Schurmechanik), patented in 1848 by Thomas D. Paine of Woonsocket, Rhode Island, and also taken up in 1855 by Wenzel Schamal in Prague, on Kail’s suggestion. This system also employs a spiral spring at the axle of the touchpiece, from which a connecting rod passes close to the associated valve casing (thereby eliminating the articulated crank), carrying near its end a loop of fine cord anchored to it at two points (at a distance from each other about equal to the valve’s diameter). The cord passes round a pulley on the rotor spindle to which it is also fastened (see fig.5). This arrangement gives an efficient and silent rotary motion, its only disadvantage being the possible breaking of the cord. String action was also part of the US patent granted in 1866 to Isaac Fiske of Worcester, Massachusetts, for a cornet with three rotary valves activated by vertical rods passing through a casing containing the spring – an arrangement which, except for the string action, very closely resembled one for which Joseph Higham had already obtained a British patent in 1857.
It is not difficult to explain why the Vienna or double piston valve (see fig.7), once so popular in central Europe, has passed almost completely out of use. Its chief advantage lies in its right-angled windways, producing a gentler tone than is currently in vogue.
In the meantime Friedrich Blühmel, a works band musician, had contested Stölzel’s primacy with the ‘box’ valve (Ger. Kastenventil; see fig.8), which he demonstrated in 1816 on a trumpet and a horn, each with two valves. He then showed a three-valved trombone in February 1818. Instruments with box valves survive in the large collections in Berlin, Nuremberg and Brussels. After considerable litigation, the two men finally joined forces. Together they secured a ten-year Prussian patent for both kinds of valve on 12 April 1818, Stölzel furthermore buying out Blühmel’s rights for 400 thalers. It is important to note that it was not the specific type of valve, but rather the general principle as applied to brass instruments, which the patent office considered protectable. Later patent applications were often refused for this reason.
Stölzel’s tubular valve (or ‘Stölzel valve’; Ger. Schubventil, Fr. piston Stoelzel), in which the lower part of its casing also serves as a windway (see fig.9), is the most common type found on instruments made before 1850, the surviving instruments often having two such valves. The first were made for Stölzel by Griesling & Schlott of Berlin (c1816–18). Their design was copied very soon by J.F. Anderst (St Petersburg, 1825), Labbaye and Halary (Paris, 1827), Pace and Köhler (London, after 1830), and even James Keat for Samuel Graves (Winchester, NH, c1837). In London, chromatic Russian brass instruments (a gift to the Second Life Guards band from Tsar Nicholas I, who had purchased such instruments from Griesling & Schlott in 1824) were heard as early as 6 May 1831, and a ‘Russian Valve or Stop Trumpet’ is illustrated on p.38 of the elder Harper’s Instructions for the Trumpet of 1835. Despite the somewhat constricted cross-tubes of the piston and the sharp angles involved, valves of this type were still in use on inexpensive French cornets as late as 1916, no doubt because they were relatively easy to make.
The next valve to claim attention was a ‘transverse spring slide’ (British patent no.5013 of 1824) devised by John Shaw of Glossop, Derbyshire, a farmer and part-time brass worker. Its application required that a large part of the main tube of the instrument take the form of a long narrow U, much like the slide of the trombone. Both limbs of the tube passed through twin pairs of piston cases set perpendicular to the plane of the U, and these were bridged by two pistons connected at the top by a cross-tube. When depressed, the paired pistons either short-circuited a section of the main tube or cut in an extra length (see fig.10). No surviving examples are known, and it seems likely that the complexity of the arrangement kept it from being generally adopted.
In 1838 John Shaw took out a patent for what he called ‘patent swivel valves for brass instruments’, and J.A. Köhler acquired the right to manufacture instruments with such valves for a ten-year period. A year or two later Köhler brought out an improved version called the New Patent Lever valve. This was very similar to the plaques tournantes or disques mobiles which the Parisian maker Halary (ii) had developed (but not patented) in 1835. Köhler sold a number of instruments with disc valves to the British Army, and no fewer than 18 to the band of the Crystal Palace at its opening in 1854. This type of valve, however (Ger. Scheibenventil), with one disc rotating against another fixed one containing the valve slides (see fig.11), generated too much friction to work rapidly enough, and it never gained acceptance.
J. Meifred: ‘Notice sur la fabrication des instruments de musique en cuivre’, Annuaire de la Société des anciens élèves des écoles nationales des arts-et-métiers, 1851; pubd separately (Paris, 1851)
C. Pierre: La facture instrumentale à l’Exposition universelle de 1889 (Paris, 1890)
A.S. Rose: Talks with Bandsmen: a Popular Handbook for Brass Instrumentalists (London, 1895, rev. 1996 with introduction by A. Myers)
B. Hague: ‘The Tonal Spectra of Wind Instruments’, PRMA, lxxiii (1946–7), 67–83
A.H. Benade: Horns, Strings and Harmony (Garden City, NY, 1960/R)
R. Morley-Pegge: The French Horn (London, 1960/R)
M. Vogel: Die Intonation der Blechbläser (Düsseldorf, 1961)
P. Bate: The Trumpet and Trombone (London, 1966, 2/1972/R)
R.E. Eliason: ‘Early American Valves for Brass Instruments’, GSJ,, xxiii (1970), 86–96
A. Baines: Brass Instruments: their and Development (London, 1976)
A. Benade: Fundamentals of Musical Acoustics (New York, 1976, 2/1990)
R.E. Eliason: ‘Brasses with both Keys and Valves’, JAMIS, ii (1976), 69–85
J.-P. Mathez: Joseph Jean-Baptiste Laurent Arban 1825–1889 (Moudon, 1977)
M. Haine: Adolphe Sax (1814–1894): sa vie, son oeuvre et ses instruments de musique (Brussels, 1980)
J. Webb: ‘Designs for Brass in the Public Record Office’, GSJ, xxxviii (1985), 48–54
C. Ahrens: Eine Erfindung und ihre Folgen: Blechblasinstrumente mit Ventilen (Kassel, 1986)
B. Kampmann: Catalogue de la collection d’instruments de musique à vent (Paris, 1986–)
H. Heyde: Das Ventilblasinstrument (Leipzig, 1987)
G. Dullat: Metallblasinstrumentenbau: Entwicklungsstufen und Technologie (Frankfurt, 1989)
E. Tarr: ‘The Romantic Trumpet’, HBSJ, v (1993), 213–61
H. Heyde: Musikinstrumentenbau in Preussen (Tutzing, 1994)
M. Lessen and A.E. Smith: ‘A New Compensating Valve System’, Journal of the International Trumpet Guild, xix/4 (1995), 47–56
A. Myers: ‘Design, Technology and Manufacture since 1800’, The Cambridge Companion to Brass Instruments, ed. T. Herbert and J. Wallace (Cambridge, 1997), 115–30
A.L. Porfir'yeva and A.A. Stepanov: ‘Kyol'bel' (Koelbel), Ferdinand’, Musical St Petersburg: Musical-Encyclopedic Dictionary, ed. A.L. Porfir'yeva (St Petersburg, 1998)
E. Tarr: East Meets West (Stuyvesant, NY, forthcoming)
or D without extra crooks.
