X-Rays Illuminate Missing Music

A newly released score of Luigi Cherubini’s opera “Médée” contains notes perhaps not heard since the late 1700s, thanks to X-ray fluorescence analysis done by scientists at SLAC National Accelerator Laboratory and England’s University of Manchester. Music scholar and score editor Heiko Cullmann had heard how SLAC scientists illuminated erased mathematical teachings by Archimedes. He approached SLAC’s Uwe Bergmann about doing the same for blacked-out portions of a 200-year-old “Médée” score. The team scanned the page in pixels of about 50 µm using a synchrotron X-ray beam. They used zinc emission signals to pick up the music bar lines and traced the music notes from their iron emission signals (Annu. Rev. Anal. Chem. 2012, DOI: 10.1146/annurev-an​chem-062011-143019). The presence of the metals in the inks was critical to the success of the project, Bergmann says. An all-organic ink would have made analysis impossible because carbon emits soft, hard-to-detect X-rays. Fortunately, the black substance obscuring the notes is carbon-based with just a small amount of iron. The paper itself is transparent to X-rays, causing notes from both sides of the page to appear in a single image. The researchers deconvoluted the music manually on the basis of the way the notes were drawn.