CREMONA, Italy — A violin, it turns out, needs to be played, just as a car needs to be driven. In this city that produced the best violins ever made, that job belongs to Andrea Mosconi. He is 75, and for the past 30 years, six days a week, he has finger-fed 300-year-old violins, worth millions of dollars, a diet of Bach, Tchaikovsky and Bartok.

It is peaceful where he works, in a chapel-turned-museum, so it jars when he compares his gentle job to the roar of Formula One racing. He is nothing but serious about what he does.

"It is not a matter of habit," Mosconi said. "When Schumacher gets to 350 kilometers an hour, do you think he ever loses his concentration," he added, speaking of the retired racing champion Michael Schumacher.

"In my case, too, I have to pay attention," he said. "You have to give your best with these instruments. They make you sweat."

He had just finished playing a few lines of Bach on the most valuable piece in this town's small but significant collection of locally made stringed instruments: a violin made in 1715 by Antonio Stradivari.

It was the kind of exercise, at once heroic and the slightest bit melancholy, and dogged by worry that the past may overshadow a less glorious future. That tension is on display at the violin museum at the city hall in Cremona, where the modern violin was born and built, to a standard not yet surpassed, by the families of Amati, Guarneri and Stradivari.

Every morning, Mosconi, the city's official musical conservationist, stands before pristine, glass cases and faces three violins by the Amatis (one of the first makers of the modern violin, from the mid-16th century), two by the Guarneris and four instruments — three violins and a cello — by Stradivari. Mosconi has no favorite: The very question is a mild affront.

"It's as if you were to ask me which of my three children I preferred," he said.

Mosconi — who was born in Cremona, began playing the violin at age 9, studied violin making and went on to teach and perform — starts his work at 8 a.m., an hour before the museum opens. He stores his tools in a tastefully concealed closet: two bows, resin, baby-soft cotton rags and jugs of distilled water for the humidifier that keeps the air at the perfect moisture to preserve the instruments.

Getting down to work, he carefully removes each instrument. He tunes them, then plays each for six or seven minutes. He starts with scales and arpeggios, then something more substantial.

"A great instrument should get great music and also a great performer," he said. A multimillion dollar violin in hand, he paused for a moment to ponder his own place. "Not that I am a great performer," he said. "But I do my work."