Stradivarius, Amati and Guarneri violins were made more powerful 'by accident'

Research from Massachusetts Institute of Technology (MIT) and the North Bennet Street School in Boston shows that violins made in the 17<sup>th and 18<sup>th centuries were the most proficient of the instruments that have ever been produced, but only because of human error in replication.

Master violin-making families, such as Amati, Stradivari, and Guarneri, crafted the instruments - in what has been dubbed the Cremonese period - that are now worth millions of pounds some 300 years later.

Acousticians and fluid dynamists from MIT spent time analysing the Cremonese-era violins and concluded that the shape and design of such instruments make them the most powerful acoustically.

One of the findings was that the thickness of the back of the violin contributes to the better sound, but what makes them the best is the shape and length of the f-holes, the area through which air escapes. MIT says that the longer this is, the more noise it can produce. However, it is thought that the elongated air holes were not intentional in the design process.

The institute claims that as one master violin maker was followed by another, the f-holes could have been made slightly longer by error as they tried to mimic the previous top-creator.

Nicholas Makris, a professor of mechanical and ocean engineering at MIT, said: "We found that if you try to replicate a sound hole exactly from the last one you made, you'll always have a little error.

"You're cutting with a knife into thin wood and you can't get it perfectly, and the error we report is about 2% ... always within what would have happened if it was an evolutionary change, accidentally from random fluctuations."