Ace kollywood director Mani Ratnam will unveil the biography of academy award winning music director A R Rahman.The book is titled 'The Spirit of Music' and will be launched on April 6, 2011. The book will be published by Om books International and has been written by film historian Nasreen Munni Kabir. “It is indeed a rare honour to publish this book. AR Rahman’s journey, like that of most great artists, is one that moves and inspires. Nasreen Munni Kabir has recorded this journey, over the last three years. This book also has a CD with AR Rahman’s compositions for free distribution with the first edition.”  , said Ajay Mago, publisher of Om Books. The historian describes the world acknowledged music director as the 'man who defined contemporary Indian music'.