X-rays resurrect 200-year-old lost opera

15 Jun 2013

Audiences can hear a 200-year-old opera by composer Luigi Cherubini in full for the first time in centuries after scientists used X-rays to reveal hidden notes.

The team used X-rays to reveal the hidden score
The team used X-rays to reveal the hidden score

At first glance the beautifully bound 1797 Luigi Cherubini opera "Médée" looks like an impeccably preserved relic of opera's golden age. However, flip to the final pages of the aria "Du trouble affreux qui me d´evore" ("The terrible disorder that consumes me") and you find thick smudges of carbon blacking out the closing lines.

When Cherubini first performed his operatic masterpiece, the critics scoffed that it was too long. The legend goes that Cherubini, in an act of defiance, blacked out the closing lines to make the piece shorter. For centuries groups have had to perform the piece in its incomplete form.

But now, for the first time in over 200 years, Cherubini's most famous opera can be heard in full thanks to scientists from The University of Manchester and the SLAC National Accelerator Laboratory at Stanford, who used X-Rays to glimpse at the lost musical notes concealed under the carbon smear.

"It was amazing to be able to see the complete aria," said physicist Dr Uwe Bergmann, interim director of the SLAC Linac Coherent Light Source. "For me uncovering the composition of a genius's work that had been lost for centuries is as thrilling as trying to uncover one of the big secrets of nature."

Cherubini was widely considered to be one of the greatest composers of his time; even Ludwig van Beethoven held him in high regard, admiring Cherubini's ability to "weave his polyphonic virtuosity, classical stylistic polish, and a truly Romantic sense of drama into music of extraordinary depth and dramatic power".

Dr Roy Wogelius, a geochemist from The University of Manchester who was visiting SLAC at the time, helped reveal the hidden notes. He said: “It was exciting to help retrieve the lost notes of the opera. We used the same X-ray technique for the manuscript as we do to acquire chemical details from fossil animals and reveal details we also had no idea we could ‘see’ until we started using synchrotron light.

“We used nearly the same set-up for the music score as for the fossils but, because the chemical composition of the ink was relatively easy to see compared to the carbon paint daubed over it, the images of the composer's pen strokes appeared even more quickly and clearly than usual. I was pleased to hear that the aria has since been performed and recorded in full.”

The synchrotron light source used to restore Cherubini's opera began as a byproduct of one of the accelerators at SLAC. Electrons moving at nearly the speed of light fire off a bit of high-energy light called an X-Ray as they zip along curves in the accelerator. These X-Rays are then collected, sorted and focused into a beam scientists can use to run experiments.

When this beam of intense X-Rays bombards matter, such as the ink on the musical score, a few electrons in the material get knocked out of their energy orbits around the nucleus of their atoms. This creates holes which get filled by electrons falling from a higher energy orbit. When an electron falls from a higher energy orbit to a lower energy orbit, the difference in energy is released as an X-Ray. This process is known as X-Ray fluorescence. Since the energy difference between orbits is unique to each element, the fluorescence X-Rays coming off a material can act like an elemental fingerprint.

When Cherubini composed Médée in 1797, ink contained a large amount of metal. In the case of Cherubini's manuscript, the handwritten notes were written with iron gall ink which, as the name suggests, contained a large amount of iron. The manuscript pages Cherubini wrote on came preprinted with the horizontal lines, called musical staffs, used to differentiate notes. These printed lines contained a high level of zinc.

By setting their sensors to look for X-Ray energies associated with zinc and iron, the scientists literally had X-Ray vision: The charcoal smudges – and even the paper itself – mostly contained carbon and would be almost completely transparent to the X-Ray beam.

The scientists focused their X-Ray beam down to 50 microns across—smaller than the width of a human hair. Slowly, the scientists scanned the document lines by line, alternatively moving left to right and right to left as the beam worked its way down the page. Each side of the page took about eight hours to scan.

Drs Webb, Bergmann and Wogelius quickly saw the hidden notes emerge on their monitor. However, they ran into a problem: the paper itself was invisible to the X-ray beam, meaning they were getting notes on both sides of the page at once during their scans.

Luckily they came up with a simple solution: a musical note is typically made up of a vertical stem attached to a circular head. In Cherubini's case, the note heads consistently attached on to the right side of the stems. By going through by hand and seeing which heads leaned which way, the single image of jumbled notes became two distinct pages of crisp musical notes. For the first time in over 200 years, Cherubini's masterpiece was complete.

"We are used to scientific experiments where you get the data and have years of work before you can make any sense of it," said Dr Bergmann. "In this case we ran the project overnight and in the morning we were done. You could read the score – it was amazing." 


Notes for editors

Images of the revealed score and an audio recording are available on request.

For further information contact:

Aeron Haworth
Media Relations
Faculty of Engineering and Physical Sciences
The University of Manchester

Tel: 0161 275 8387
Mob: 07717 881563
Email: aeron.haworth@manchester.ac.uk