It is now generally agreed that the Iliad and Odyssey evolved over many centuries, originally as songs. Wandering around the homesteads and halls of the Greek world were the singers, men of prodigious memories who had mastered the art of communication through verse. Research in the Balkans, notably in the early part of the last century by the American scholar Milman Parry, has shown how formidable the skills of such singers could be and how sophisticated their techniques. One Bosnian Muslim was found to have held in his mind twice as many lines as the Odyssey and Iliad combined. The singers did not simply rely on memory. Serial recordings of the survivors of this tradition show they have an extraordinary ability to improvise, never repeating the stories in the same way, and continually developing their themes.