Dr Johnson’s dictionary has no entry for synaesthesia: I don’t suppose it figured much in 18th-century consciousness, and if it had, he wouldn’t have believed in it. But the enchanting Georgian town of Lichfield, the doctor’s birthplace and home to his gouty-looking statue in the main square, took the idea seriously during its annual festival last week. Lichfield Festival’s composer-in-residence, Deborah Pritchard, creates music that is largely governed by the relationship she perceives between sound and colour.