Of the many golden ages proclaimed over history, there is at least one -- the golden age of the violin, in northern Italy during the late 17th and 18th centuries -- that remains today provably, certifiably golden.

And it is the inexplicable gold of this tiny handful of craftsmen from Cremona that is the subject of a "NOVA" segment called "The Great Violin Mystery" on Channel 26 at 8 tomorrow night.

Near the opening we are taken to an auction of the "Healy Strad" recently at Sotheby's in New York. The auctioneer starts at $100,000 before a packed house, and in increments of $10,000 and $20,000 the price climbs through the standard gestures of blinks and hand signals to a top of $180,000 in about a minute. And if anyone suggests that such a 250-year-old fiddle may be inflated in value like a lesser Impressionist or a Navajo rug, just consider this.

Many thousands more people are playing violins now than were at the time of the Stradivaris and Guarneris of Cremona. Yet since the death in 1945 of Giuseppe Guarneri 'del Gesu,' the last and some think the greatest of those lines, apparently not a single violin has been built anywhere that measures up to the combination of endurance, brilliance richness and power of the best instruments from that era.

But if Cremona's techniques have consistently eluded subsequent violin makers, it has not been for lack of searching. There have been repeated epidemics of speculative fever. And, as in most such quests, the speculator has counted all or nothing on the strength of a single find. Many tried to break the formula of that Venetian varnish.Did the Cremonans get their spruce for the tops of the boxes from a subsequently untapped grove in Lombardy? Likewise, the maple bottoms?

With this century, research has turned more to application of the laws of physical and engineering. It might be called the aerodynamics of the violin soundbox. And it is on that line of research that tomorrow night's show focuses.

The work of William Fry, a high-energy physicist at the University of Wisconsin and an amateur violinist, is examined in detail. Fry has conducted hundreds of experiments in his cellar on the interrelationships of the parts of the violin sound box -- the top, the back plate, th soundpost, the bass-bar, the f-holes and the bridge. In the process he confesses to having destroyed a few instruments, and the most dramatic moment in the television hour comes when Fry starts dropping magnets willy-nilly inside a Milwaukee violinist's Guarneri to measure how its vibrations are distributed.

The implicit suggestion in the show is that Fry has achieved a breakthrough toward solving the Great Violin Mystery. Maybe. But any such declaration is premature. He certainly hasn't built any great violins yet.