Which 12th-century abbess wrote medicine, music and her own invented language?

Hildegard of Bingen, who ran an abbey on the Rhine and produced theology, two books of medicine and natural history, seventy-seven surviving pieces of music, a morality play with parts to sing, and a constructed language of about a thousand words with its own alphabet, the Lingua Ignota, whose purpose nobody has established.

Her authority came from visions she had had since childhood and kept quiet about until she was in her forties, when she wrote to Bernard of Clairvaux and eventually secured papal approval to publish - which converted a private experience into a licence to speak. She used it to lecture bishops, tour preaching, correspond with an emperor, and separate her nuns from the men's monastery they were attached to over the abbot's objection.

The visions were accompanied by illness and by light, and a neurologist's suggestion that they were migraine with aura has been repeated ever since - it is a reading of her descriptions rather than a diagnosis, and it says nothing about the content. Her music is what carried her out of specialist interest: soaring, wide-ranging melodic lines quite unlike the plainchant around them, which had a substantial revival on record from the 1980s.