HARPSICHORDS AND CLAVICHORDS MUSIC 318 PLUCKED STRING INSTRUMENTS HARPSICHORDS AND CLAVICHORDS SCIENCE OF SOUND, CHAPTER 14 PHYSICS OF MUSICAL INSTRUMENTS, CHAPTER 11 “ANALYSIS OF THE DESIGN AND PERFORMANCE OF HARPSICHORDS” (N.H.FLETCHER, ACUSTICA 37, 139 (1977).

HISTORY THE IDEA OF USING A KEYBOARD TO CONTROL THE PLUCKING OF STRINGS SEEMS TO HAVE DEVELOPED IN THE LATE 14TH CENTURY, WITH A HARPSICHORD-LIKE INSTRUMENT APPEARING IN THE 15TH CENTURY. MOST OF THE DEVELOPMENT OF THE HARPSICHORD TOOK PLACE IN THE 16TH AND 17TH CENTURIES, FIRST IN ITALY AND THEN IN FLANDERS, GERMANY, AND ENGLAND. HARPSICHORDS MAY HAVE ONE OR TWO KEYBOARDS, AND EVEN A PEDAL KEYBOARD (SIMILAR TO A PIPE ORGAN). PLASTIC PLECTRA HAVE NOW LARGELY REPLACED THE TRADITIONAL QUILLS. IN ADDITION TO THE STANDARD HARPSICHORD IN WHICH THE STRINGS RUN STRAIGHT AWAY FROM THE PLAYER, THERE ARE TWO SMALLER VERSIONS USING THE SAME PLUCK ACTION. ONE, KNOWN AS THE VIRGINAL HAS A RECTANGULAR CASE WITH THE STRINGS RUNNING NEARLY PARALLEL TO THE KEYBOARD. ANOTHER KNOWN AS THE SPINET, HAS A TRIANGULAR CASE WITH THE STRINGS RUNNING OBLIQUELY TO THE KEYBOARD.

HARPSICHORD

MODERN FLEMISH HARPSICHORD BY AUSTRALIAN CAREY BEEBE BASED ON CLASSICAL INSTRUMENTS BY THE 17TH CENTURY MAKER ANDREAS RUCKERS. THE KEYBOARD COMPASS HAS BEEN EXTENDED DOWN TO G3 IN THE BASS AND UP TO D6 IN THE TREBLE. THE SMALL PROTRUSIONS ON THE RIGHT SIDE (CHEEK) ENABLE THE PLAYER TO ENGAGE EITHER OF THE TWO SETS OF JACKS BY SLIDING THE REGISTER ON OR OFF

HARPSICHORD ACTION (SIMPLIFIED)

HARPSICHORD ACTION EACH JACK PASSES THROUGH A SLOTT END UPPER REGISTER AND A LOWER GUIDE, AND THE PLAYER CAN MANIPULATE THE UPPER REGISTER TO MOVE THE WHOLE SET OF JACKS SO THE PLECTRA ARE JUST OUT OF RANGE OF NORMAL PLUCKING CONTACT WITH THE STRINGS THAT DO NOT SOUND.

HARPSICHORD ACTION ACTION OF A FLEMISH HARPSICHORD. IN THIS INSTRUMENT THERE ARE TWO CHOIRS OF STRINGS, THE SHORTER 4-FT CHOIR AND AN 8-FT CHOIR. THE LEATHER PADS OF THE BUFF STOP ARE VISIBLE BEHIND THE 4-FT TUNING PINS

SCALING THE FUNDAMENTAL FREQUENCY OF A VIBRATING STRING DEPENDS UPON ITS LENGTH, DIAMETER, AND TENSION, AND MASS PER UNIT LENGTH: THE UPPER STRINGS ARE NORMALLY MADE OF IRON AND THE LOWER ONES OF BRASS, WHICH IS MORE DENSE.

SCALING OF STRING SOUND LENGTH, PLUCKING POSITION, AND STRING DIAMETER FOR THE 8-FT AND 4-FT STRING CHOIRS OF RUCKERS REPRODUCTION

HARPSICHORD SCALING SCALING OF STRING DIAMETER FOR 4-FT AND 8-FT STRING CHOIRS

POINT OF PLUCKING EACH STRING A MAJOR DESIGN FEATURE IS THE POSITION AT WHICH EACH STRING IS PLUCKED. IF A STRING IS PLUCKED AT A POSITION 1/n OF ITS LENGTH FROM ONE END, THERE IS A STRONG DOWNWARD FORCE FOR A FRACTION 1/n OF A PERIOD, FOLLOWED BY A MUCH WEAKER UPWARD FORCE FOR THE REMAINDER OF THE PERIOD. HARMONICS BELOW THE nth ARE STRONG, THE nth HARMONIC IS MISSING, AND HARMONICS ABOVE THE nth DECREASE WITH INCREASING FREQUENCY.

STRING FORCE ON THE BRIDGE WAVEFORM OF BRIDGE FORCE FOR PLUCKING AT 1/5 THE STRING LENGTH (a) AND 1/20 OF THE LENGTH (c). SPECTRA ARE SHOWN IN (b) AND (d)

STRUCTURE STRINGS TRANSMIT VIBRATIONAL ENERGY TO THE SOUNDBOARD BY MEANS OF THE BRIDGES. THE SHAPES OF THE MODES OF VIBRATION OF THE SOUNDBOARD ARE INFLUENCED BY THE OVERALL SHAPE AND STIFFNESS, AND BY THE RIBS AND BRIDGES ATTACHED TO IT. THE ENCLOSED AIR ALSO STRONGLY INFLUENCES THE MODES OF VIBRATION, AND RADIATES CONSIDERABLE SOUND THROUGH THE ROSE HOLE.

VIBRATIONAL MODES OF A HARPSICHORD SOUNDBOARD

SOUND QUALITY AND DECAY TIME DECAY TIMES FOR RUCKERS HARPSICHORD

CLAVICHORDS COPY OF A DOUBLE-FRETTED CLAVICHORD MADE IN THE 18TH CENTURY BY CHRISTIAN HUBERT. THE BRIDGE IS MOUNTED ON A THIN SOUNDBOARD WHICH FORMS THE TOP OF A CAVITY

CLAVICHORD ACTION EACH KEY IS PIVOTED ON THE BALANCE RAIL AND WHEN IT IS DEPRESSED, THE BRASS TANGENT STRIKES THE PAIR OF STRINGS CORRESPONDING TO THAT NOTE.

STRING LENGTHS AND DIAMETERS OF CLAVICHORD STRINGS FROM C2 TO F#2 ARE OF RED BRASS ® AND ALL OTHER STRINGS ARE OF YELLOW BRASS (Y)

CLAVICHORD SOUND UNLIKE THE HARPSICHORD, THE CLAVICHORD PLAYER HAS DIRECT DYNAMIC CONTROL OVER THE SOUND BY VARYING THE SPEED AT WHICH THE TANGENT STRIKES THE STRING AND THE FORCE WHILE THE SOUND IS SUSTAINED. THE FORCE ON THE BRIDGE HAS A SPECTRUM THAT FALLS SMOOTHLY AT ABOUT 8 dB/OCTAVE. BECAUSE THE DISPLACEMENT OF THE STRING BY THE TANGENT INCREASES ITS TENSION BY A SMALL AMOUNT, THE PLAYER CAN CREATE A PITCH VIBRATO BY VARYING THE FINGER FORCE ON THE KEY. THE FACT THAT EACH NOTE IS PRODUCED BY TWO STRINGS PRODUCES AN EFFECT SIMILAR TO THAT FOUND IN PIANOS. IMMEDIATELY AFTER STRIKING, THE STRINGS VIBRATE IN PHASE, AND VIBRATIONAL ENERGY IS TRANSFERRED RAPIDLY TO THE BRIDGE AND SOUNDBOARD, LEADING TO A RAPID INITIAL SOUND DECAY WITH AN “AFTERSOUND” AFTER THE TWO STRINGS GET OUT OF PHASE. THIS LEADS TO AN INITIAL CLARITY OF SOUND COMBINED WITH A MELLOWNESS.