Henry Charles Lea's History of the Inquisition, first published in 1887, says that, "In Ireland the fiery temper of the Franciscan, Richard Ledred, Bishop of Ossory, led him into a prolonged struggle with presumed heretics – the Lady Alice Kyteler, accused of sorcery, and her accomplices". In spite of opposition, says Lea, the bishop "had the satisfaction of burning some of the accused in 1325". Lady Alice escaped, but her servant Petronilla de Meath was burned alive at the stake as a witch.

The bishop had a purifying view, too, on what should be sung in church, and he left a body of texts included in the Red Book of Ossory, some of which the new ensemble Anakronos has set on their first recording. The approach is eclectic. The pure-voiced O'Leary and her friends – saxophonist Nick Roth, clarinettist Deirdre O'Leary and percussionist Francesco Turrisi – have drawn on a range of medieval musical sources and O'Leary describes the group as deconstructing the material "with learned disregard for proper chronology".

The music is processed with plenty of electronic support and ambience in a range of musical styles from mock-medieval to ethnically toe-tapping to jazzy, with the instruments delighting in arabesques drawn around the more considered movement of the voice.