Music in the Daily Life of Vermeer
The Dulcian or Curtal (3)

Structure and playing technique of the dulcian

Dulcians are usually made of maple or sycamore although cherrywood, cedar, ebony, oak, rosewood or walnut have been used with varying success.

Schematic cross-section of the double bore.

Three forms of dulcian bells:
(a) widely flared, (b) almost cylindrical, (c) gently flared.

The distinguishing feature of the dulcian is its conical double bore: a smaller, smoothly tapered downbore, started from one end of the workpiece, and a broader upbore, started from the other end and ending into the bell. The two bores should lie as close as possible to each other, but not too close as to weaken the instrument and not too far lest it be clumsy to handle. The bell is turned on a lathe, either integral with the body or turned from a separate piece of wood.

There are principally three forms of bells. The bell may be open or covered, it is called gedackt (from German: 'Dach'/ Dutch: "dak"  = roof). According to Praetorius, the cover makes the tone "considerably softer and more beautiful" which allows it to be played with softer sounding instruments (e.g. string instruments) or for accompanying the singing ( in sacred music).

Once the turning of the bores is completed, they are joined at the butt end, either by removing the bottom of the dividing septum (the point where the bores nearly meet the bottom), or by carving an interconnecting circular hole near the bottom of the septum. Then one or two wooden plugs are inserted to seal the bore and a brass butt cap or band is usually fitted.

The keys are attached to the instrument by saddles or lugs, fixed to the dulcian's body, sometimes by a brass band which circles instrument. The front key may either have a double- or a single-touch. Springs and keyflaps are fitted, and the keycovers nailed to the body or attached to a brass band.

The crook or bocal is made by gently hammering a length of brass around a mandrel or arbor to form a tapered conical tube. After removing the mandrel the crook is filled with pitch and bent over a former to the required shape. When ready, the crook will be inserted into the small bore with a crook socket inside and the reed attached to the free end of the crook.¹

As the reed is of enormous importance, not only for sound of the dulcian but for the playing technique as well, it is useful to have a closer look at its specific forms, features and modes of action.

The double reed

Modern reed (side- and front view for the bassoon.

Drawing of a fagot reed in Mersenne's Harmonie Universelle (1636/48).

The double reed  is usually made of a folded, carefully manufactured cane of Arundo donax.  The unprofiled end of the cane is shaped into a tube and bound with thin metal wires and additional binding of thread.²

The earliest reed-making instructions are known from the Instrumentälischer Bettlermantl (mid-17th century). According to P. White's ground-breaking research (1992-1994)³ 17th-century reeds were built on staples, were relatively long and narrow, bound with waxed thread rather than metal wire, and scraped to a V or U shape.

The principle function of the reed is to convert the energy of an air stream issuing from the lungs of the player into vibrations of the two reed blades. These vibrations  are transmitted to the air in the reed interior to the large column of air in the dulcian's (or bassoon's) sound tube. The instrument's vibrations cause audible air frequencies. The sound tube serves as a resonator producing a certain compass of tones (up to two and a half octaves) by the vibrating air column acting immediately on the lengthening or shortening of the sound tube by the closing or opening of the finger- or thumbholes resp. the keys.

Reed performance varies widely. Together with a carefully developed embouchure  a well-trained player is able to maintain correct pitch, create al timbre or control the volume (together with the muscles and controlling lung action), all with the assisting double reed.

The playing technique of the dulcian

The dulcian, namely the bass dulcian, is one of the most difficult instruments to play and requires considerable physical and mental strength. The player has hold the instrument with both hands and use all fingers and both thumbs for fingerings which can be at times quite complicated. His lips play a very important part in holding and pressing the reed, the tongue is active in several respects, the muscles of the mouth cavity are used to influence tone color, and the lungs have to supply sufficient air for blowing in a controlled manner.

Playing the dulcian is not just a matter of "breathing," it is the art of inhaling and exhaling. The player must inhale much quicker than he normally does. Exhaling is rather complicated because it is in exhaling itself that the instrument is made to speak, blowing air through the reed's slit aperture. The exhaling has to be adapted to the tones to be blown, the rhythm of the piece and the strength to be used to play it.

Together with the respiratory system, the mouth cavity, lips and tongue all play an important part in the blowing technique, either for the volume (from pianissimo to forte) or for the various forms of playing a sequence of tones (legato, staccato, tenuto or spiccato).

As with all wind instruments playing, the lips are very important. They hold the reed, and, by altering pressure, particularly with the upper lip, controls the embouchure which not only plays part in tone generating but also controls the overblowing of tones, the true pitch and also, to a certain degree, tone color.

Of all wind players, only the dulcian player requires significant use of the thumbs which must retain a great agility. Most wind players use their thumbs for holding their instrument.

The dulcian is held by the right hand at the lower part of the instrument, operating the fingerholes 4 to 6 (see diagram above), the front key (7) and, at the back-side, the thumbholes 8 (key) and 9. The left hand holds the upper part with the fingerholes 1 to 3 and the thumbhole (10) on the back-side.

The dulcian's rather intricate fingering is the consequence of the instrument's particular construction. Whereas the recorder and shawm are made of a single straight sound tube, the dulcian has two parallel tube sections, connected at the base by a semicircular tube to shorten its excessive length for convenient handling. By bending the tube back on itself, the narrowest part, in which the distinct tones are generated, comes to lie next to the wider part in which the lowest tones are created.

In fact, there exists no strict system of fingering, even though players adopt a general pattern for the first two octaves. The lack of a set system also depends also on the form of the particular instrument, together with the kind of reed and crook. Alternatives in fingering can improve sound quality and/or pitch.

The diagram to the right shows, perhaps, the only surviving period fingering table by the German composer, music teacher and writer Daniel Speer (1636-1707) from his Grundrichtiger Unterricht der musicalischen Kunst oder Vierfaches Musicalisches Kleeblatt (1687, revised edition 1697).

Together with a short description of the 'Bass-Fagott' and its playing the edition contains two sonatas for three fagotts, in the MP3 sound file to the right played by dulcians (with organ continuo).