I just read the definitive biography of Kishore Kumar, written by Kishore Valicha, and published by Penguin India. Very analytical (given that the author has a PhD in Film Studies, that was to be expected), but contains a good number of anecdotes about Kishore-da. It also contains excellent background information on the Hindi film industry. The emergence of the stars in the 1950s (Raj Kapoor - Dilip Kumar - Dev Anand) and the differing themes and subjects of films are explored.
In the context of Kishore Kumar as a comic actor, Valecha argues that prior to Raj Kapoor's integration of the comic with the main ccharacter, "comedy" was not seen as mainstream Hindi cinema. He also goes on to describe Kishore Kumar's unique comic talents, and spontaneous energy.
In the most significant part of the book, Valecha traces Kishore Kumar as a singer through the 1950s to the 1980s. In the process, he presents nice analysis of the evolution of Hindi film music, from its classical/ folk Indian roots, to the influence of western music and orchestration. He also describes in detail the musical styles and inspirations of various music directors through those decades. Kishore Kumar's unique, untrained voice, and ability to express emotion through his voice, and improvisational skills are also mentioned in great detail, with several examples of his best songs.
Valecha also describes Kishore Kumar's personality and its various contrasting traits. The child in him that possesses boundless energy, the loneliness, the longing for the simple life of Khandwa and other uniquely Kishore facts creates a nice portait.
On the whole, it is an excellent book. I found it to be a bit too analytical for my taste.