Medea’s final aria, hidden by Cherubini, sees the light of day after 200 years under charcoal.

The missing concluding aria to Luigi Cherubini’s 1797 Médée (better known in the Italianised form as Medea) has been revealed using X-ray techniques at Stanford University’s SLAC National Accelerator Laboratory.

Cherubini is believed to have removed the aria after criticisms of the opera’s length but he didn’t throw it away, merely smudged it over with a think layer of charcoal. Powerful X-ray light has now allowed it to be transmitted to computer screens for easy viewing.

Cherubini was considered by many of his contemporaries to be one of the greatest composers of his time. Maria Callas, who famously brought the opera back into the public domain in the 1950s after a century of neglect, never sang the coda to the piece. The lost aria, Du trouble affreux qui me dévore (The terrible disorder that consumes me) arguably adds an even more dramatic conclusion to the tragic tale.

“It is very exciting,” said Stanford physicist Uwe Bergmann. The device, known as a synchrotron “can unlock the secrets of nature…But it can also find things that are important to our human culture – with an impact...