A study conducted by a team of NTU chemists hoping to elucidate the secret behind the beautiful tones produced by Stradivarius violins was covered by over 100 international media outlets, including the New York Times, Washington Post, The Times of London, and Yomiuri Shimbun, following its publication in the Proceedings of the National Academy of Sciences in December. In the study, Prof. Hwan-Ching Tai, Prof. Jerry Chun-Chung Chen, and Prof. Hao-Ming Chen analyzed the chemical compositions of wood shavings removed from Stradivarius violins, demonstrating that the treasured violins' maple wood possesses very different chemical properties compared to modern violin maple.

Previously, many experts regarded Antonio Stradivari's lost varnish recipe as his greatest secret. After decades of scientific analysis of the renowned luthier's varnish composition, there is little evidence to suggest that his varnish might have introduced extraordinary acoustical properties. As an internationally recognized expert on Stradivari's varnish, Prof. Tai has noticed that fewer and fewer violin makers now regard the varnish as the key to Stradivari's tone. He believes that we should instead investigate the chemical properties of the wood.

Prof. Tai acquired maple specimens from four Stradivari instruments and one Guarneri. Nuclear magnetic resonance revealed that all of the historical maples exhibited hemicellulose degradation of around one-third over 300 years. Hemicellulos is the most hygroscopic component, and its degradation leads to reduced moisture absorption and reduced internal damping, allowing the wood to vibrate more freely.

Elemental analyses showed that Stradivari's Cremonese maple also appeared to have been infused with salts of sodium, potassium, and calcium. Alum, borax, zinc sulfate, and copper sulfate also appeared to have been added. The combination of these minerals probably served the purpose of "salt seasoning," providing biocidal protection against fungi and worms, and may have promoted the crosslinking of wood fibers. Such mineral treatments were unknown to European violin makers and absent in antique violins from other regions or countries.

Moreover, maples from Stradivari violins and cellos showed marked differences in their molecular structures. As the wood was gradually heated to 600 degrees Celsius, there was an extra peak in the heat-releasing curve of the violin maples that was absent in the cello maples and natural maple. The extra peak suggested reduced molecular adhesion between cellulose and lignin in the wood, likely caused by the high-frequency vibrations of violin playing.

Hence, the chemical distinctions between Stradivari's maple (in its current state) compared to modern maple can be attributed to three factors: initial chemical treatment, age-dependent chemical decomposition, and molecular rearrangement due to long-term vibration. Prof. Tai's findings may help explain why it has been so difficult to reproduce the acoustic properties of Stradivari violins using new wood materials.

However, current studies have only examined the maple in the back plat; the spruce in the front plate has not been investigated, and the front plate is supposedly even more important for violin acoustics. Prof. Tai and his team have begun to analyze Stradivari's spruce samples, hoping to uncover more secrets hidden within these unique cultural treasures.