I. Sonora Contrabassoons:
Crook-Tube Alteration
The two holes controlled
by the A register key and the one hole controlled by the D register
key on modern contrabassoons consist of small perforated bushes
soldered to the crook tube and communicating with the windway.
Inspection of my Alder-Sonora contrabassoon, an instrument dating from 1981, revealed that the perforated bushes project into the bore of the crook tube for approximately 2 millimetres. There thus exists an obstruction to the free passage of air, and an obstacle to the setting-up of a perfectly resonating air column within the instrument.
The offending projections can be removed by carefully filing them down with a circular file of fine cut (to those who live in the backwoods, I can reveal that a 7/32" Oregon chainsaw file is admirable!). Care must be taken to avoid scoring the walls of the crook tube, and also to remove all metal filings using an oily rag and a chamois-leather bassoon swab (which must thereafter not be used on a bassoon as the residue of filings can score the wing-joint ebonite lining). Approximately 0.2 mm of the projection should be retained; its function is to prevent water accumulating in the speaker-key holes, and leaving a small projection ensures that this function is preserved.
The result of this work was, for my instrument, to improve considerably the steadiness and intonation of the overblown notes, particularly e'b, e' and f' and also tenor f# and g, to improve the tone quality generally, and to facilitate production of the high register (c" and above).
II. Extreme High Notes
On The Contrabassoon
The two standard fingering charts for the German-system
contrabassoon (C.A. Biggers: The Contrabassoon, a Guide to
Performance and Seltmann & Angerhofer Das Fagott Vol.
VI) give fingerings ascending to f".
Shown below are fingerings for the next four semitones...
... where L.H. Thumb 1,2 and 3 are the D register, A register, and C sharp keys respectively.
These notes are required in solo works such as Donald Erb's Concerto and Jeno Takacs' Quodlibet. The g"sharp - a" glissando in the latter work is easily accomplished by the gradual release of key RH1.
[Robert Kay is a bassoonist and contrabassoon ist from Ledbury, Herefordshire, England Ed.]
