The tone of a keyboard instrument is also affected by its general outline, the material and thickness of the soundboard, the length and material of the strings, and the type of case construction. The case must be strong enough to counteract the tension of the strings and yet light enough to allow the sound to resonate. [Illustration: 1. Harpsichord action. _Photo: Robert Lautman._] Among the Smithsonian’s extensive keyboard collection are fine examples of harpsichords that represent several of the major national trends in harpsichord building: the Flemish, Italian, English, and French. _Flemish Harpsichords_ Antwerp was the harpsichord-making center of northern Europe during the 16th and 17th centuries. The earliest examples of harpsichords had only one keyboard and one or two sets of 8′ strings. The progressive Flemish makers added a second keyboard and another set of strings, tuned an octave higher than the others, which allowed a wider range in pitch and more variety in sound. Later French and English harpsichords were largely derived from the Flemish style. Virginal, _1620; made by Andreas Ruckers, Antwerp One manual; Range C/E-c³ (apparent); 1×8′_ [Illustration: 2. Ruckers virginal: Plan view.] [Illustration: 3. Ruckers virginal: Full view.] [Illustration: 4. Ruckers virginal: Detail of keyboard. _Photo: Robert Lautman_] [Illustration: 5. Ruckers virginal: View of soundboard and lid. _Photo: Robert Lautman_] Instruments built by the famous Ruckers family were and are still highly prized. Although simply painted on the exterior, the case of this virginal is decorated on the inside in characteristic Ruckers style. Block-printed papers cover the interior of the case; the inside of the lid bears a Latin motto and the soundboard is painted with flowers and arabesques. Figure 4 illustrates a detail of the block printing, and of the keys. The arcades on the end of the keys appear to be cut from several layers of leather which were then applied to the key fronts. This instrument is tuned a fourth higher than it might appear. When the C key is pressed, the note sounded is F, a fourth above. _Short-Octave Tuning_ Since chromatic notes in the lowest octave of the keyboard were not often needed in the music of the 16th and 17th centuries, the practice of short-octave tuning was adopted. Although the lowest note on a short-octave instrument appears to be E, the range was actually extended down to C. (The notation C/E indicates this arrangement.) [Illustration: NORMAL TUNING] [Illustration: SHORT-OCTAVE TUNING] A typical short-octave instrument of the 16th and 17th centuries would be tuned in the following manner: E (1) is tuned down to C (I); F♯ (2) tuned to D (II); and G♯ (3) tuned to E (III). Harpsichord, _1745; made by Johann Daniel Dulcken, Antwerp Two manuals; Range FF-f³; 2×8v, 1×4′, lute_