Instruments: The Ophimonocleide
An instrument, with its one open-standing key, that solved an intonation problem of all bass horns and serpents.
The ophimonocleide, introduced in 1828 by Jean-Baptiste Coeffet, displays the traditional characteristics of a bass horn; however, the design offered two features that addressed traditional weaknesses of upright serpents: one well-placed, open-standing key (providing the namesake for the instrument) and the most dramatic and pronounced (parallel) tuning slide permitting the most variation in pitch of any upright serpent.
to download a high density image of an ophimonocleide
Please include the following photo credit
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© Craig Kridel,
Berlioz Historical Brass
For a further description of the different types of bass horns, see
Bass horns and Russian bassoons
by Craig Kridel
Measurements of air column with the instrument pitched at A=440
One important designation among all upright serpents is the configuration of finger holes for the lengthening of the air column. Using Mendelssohn's 1824 line drawing of the English bass horn (sent in a letter to his sister, Fanny), finger holes have been placed in order on the air column as a way to display their positioning for the ophimonocleide.
Such an airhole design creates a series of cross-fingerings (with the 5th fingerhole) that alters the standard lengthening of the aircolumn. Some instruments include a split entry into aircolum for the 4th fingerhole.
Clearly, the ophimonocleide is an experimental instrument that addressed many of the perennial problems of bass horns.
A pompe, a double slide, enables the pitch to be altered from "opera" pitch to "cathedral" pitch. In fact, lengthening the pompe and bocal permits the instrument to be raise or lowered a minor third. Such variations alters completely the fingering patterns.