obody really knows why。 It's quite humbling； Vincent； to realize we can land a spaceship on Mars； we can build a machine to perform a trillion calculations a second； we can split the nucleus of the atom…but we still cannot make a better violin than could a man puttering around in a simple workshop three centuries ago。〃
〃Well； hewas Italian。〃
Pendergast laughed quietly。 〃One of the beautiful things about a Strad is that it has to beplayed in order to maintain its tone。 It's alive。 If you leave it in a case； it loses its tone and dies。〃
〃What about these？〃
〃They are taken out and played at least once a week。 Cremona is still the center of violinmaking； and there are many eager volunteers。〃
He clasped his hands behind his back； turned。 〃And now； for thereal reason we came to Cremona。 Stick close behind me； please； and don't get lost。〃
Pendergast led the way through a maze of back passages and narrow staircases to a side alley behind the palazzo。 There they paused at least a minute while Pendergast made a careful inspection of the alley and surrounding buildings。 Then； moving very quickly； he led D'Agosta through a winding series of ever more tortuous medieval streets； the ancient brick and stone buildings crowding in above。 Some of the streets were so narrow they were dark despite the midday sun。 Now and then； Pendergast would duck into a doorway or side alley and make another visual scan。
〃What's up？〃 D'Agosta asked at one point。
〃Just caution； Vincent； habitual caution。〃
They finally arrived at a street so narrow it could hardly admit a bicycle。 It twisted into a dead end at what appeared to be a deserted shopfront； a plate…glass window rudely affixed to a medieval stone arch。 The plate glass was cracked and taped and opaque with dirt。 A metal grate had been fitted and locked over the front； where it seemed to have rusted in place。
Pendergast slid his hand through the grate and pulled a string。 There was a small tinkle in the shop beyond。
〃Would it promise your investigation pletely if you told me who we're visiting now？〃
〃This is the laboratory and workshop ofil dottor Luigi Spezi； one of the world's foremost experts on Stradivari violins。 He is a bit of a Renaissance man himself； being a scientist and engineer as well as a fine musician。 His re…creations of the Stradivari violins are among the best in the world。 But I warn you： he is known to be a little cranky。〃
Pendergast pulled again； and a voice rumbled from the back。〃Non lo voglio。 Va' via！〃
Pendergast rang again； insistently。
A gray shape materialized behind the glass： an enormous； stooped man in a leather apron with long gray hair and a gray mustache。 He waved both hands at Pendergast in a shooing motion。〃Che cazz'！ Via； ho detto！〃
Pendergast took out a business card； wrote a single word on the back； and slipped it through the mail slot in the door。 It fluttered to the floor。 The man picked it up； read the back； and went very still for a moment。 He looked up at Pendergast； looked down at the card…and then began the laborious process of unlocking the door and raising the grate。 Within a minute； they had stooped beneath the arch and were standing in his shop。
D'Agosta looked around curiously。 The walls of the shop were almost pletely covered with the hanging bellies； backplates； and purflings of violins in various stages of carving。 It had a pleasant smell of wood； sawdust； varnish； oil； and glue。
The man stared at Pendergast as if he were staring at a ghost。 He was wearing a dirty leather apron； and he removed a pair of sawdust…covered glasses in order to peer at the agent more closely。
〃So； Aloysius Pendergast； Ph。D。；〃 he said in almost flawless English。 〃You have gotten my attention。 What is it you want？〃
〃Is there a place where we can talk？〃
They followed him through the confines of the narrow shop…perhaps eight feet wide…to a much larger space in the back。 Spezi indicated for them to sit on a long bench。 He himself perched against the corner of a worktable； folded his hands； and stared。
In the rear wall； D'Agosta could see a stainless…steel door； grossly out of place； with a single small window。 On the far side of the window was a gleaming white laboratory； racks of puter equipment and CRTs bathed in unpleasant fluorescent light。
〃Thank you for agreeing to see me； Dottor Spezi；〃 Pendergast said。 〃I know you are a very busy man； and I can assure you we will not waste your time。〃
The man bowed his head； mollified slightly。
〃This is my associate； Sergeant Vincent D'Agosta of the Southampton Police Department； New York。〃
〃Very pleased。〃 The man leaned forward and shook his hand。 He had a surprisingly strong grip。 Then he sat back again and waited。
〃I propose an exchange of information；〃 Pendergast said。
〃As you wish。〃
〃You tell me what you know of Stradivari's secret formulas。 I will tell you what I know of the existence of the violin mentioned on my card。 Naturally； I will keep your information secret。 I will write nothing down and speak to no one about it； except to my associate； who is a man of plete discretion。〃
D'Agosta watched the man's deep pale eyes stare back at them。 He appeared to be thinking about； perhaps even struggling with； the proposal。 Finally he nodded curtly。
〃Very well； then；〃 said Pendergast。 〃I wonder if you could answer some questions about your work。〃
〃Yes； but first： the violin。 How in the world…？〃
〃First things first。 Tell me； Dottore…since I am a man who knows nothing about violins…tell me what makes the sound of a Stradivarius so perfect？〃
The man seemed to relax； evidently realizing he was not dealing with a spy or petitor。 〃This is no secret。 I would characterize it as very lively。 It is aninteresting sound。 On top of that； it has a bination of darkness and brilliance； a balance between high and low frequencies…a tone that is rich but as pure and sweet as honey。 Of course； each Strad sounds different…some have a fatter tone； others are lean； even harsh； some are thin and quite disappointing。 Some have been repaired and rebuilt so many times they can hardly be called original。 Only six Strads； for example； retain their original necks。 When you drop a violin； it's always the neck that breaks。 But there are about ten or twenty that sound almost perfect。〃
〃Why？〃
At this； the man smiled。 〃That； of course； is the question。〃 He rose； went to the steel door； unlocked it； and swung it open； revealing two hard…disk recording workstations and racks of digital samplers； pressors； and limiters。 The walls and ceiling were covered with acoustic foam paneling。
They followed him in； and he shut and locked the door behind them。 Then he switched on an amplifier； pulled up the faders on a nearby mixing console。 A low hum began to sound from the reference speakers set high in the walls。
〃The first really scientific test done on a Stradivarius was performed about fifty years ago。 They hooked a sound generator to the bridge of a violin and had it vibrate the instrument。 Then they measured how the violin vibrated in return。 An absurd test； really； because it has nothing to do with the way a violin is played。 But even such a crude test showed the Strad gave back an extraordinary response in the two…thousand…to…four…thousand…hertz range…which； not at all coincidentally； happens to be the range of sound that the human ear is most sensitive to。 Later； high…speed puters allowed real…time processing of a Strad being played。 Let me give you an example。〃
He turned to one of the digital samplers； used an attached keyboard to select an audio sample； sent the output to the mixer。 The sweet sound of a violin filled the room。
〃This is Jascha Heifetz playing the cadenza of Beethoven's violin concerto on the Messiah Stradivarius。〃
A plex series of dancing lines appeared on a monitor sitting behind the mixer。 Spezi pointed at them。
〃That is a frequency analysis from thirty to thirty thousand hertz。 Look at the richness of the low…frequency sounds！ They give the violin its darkness； its sonority。 And in the two thousand to four thousand range I mentioned； see how lively and robust it is。This is what fills the concert hall