For Keller, Haydn emerges as the founder of the quarter form and remains its greatest exponent. In discussing the tension between the intimate quartet and the larger, more public symphony, Keller argues, Haydn too wrote for the concert hall in London - without, however, sacrificing the tiniest particle of the quartet's expressive range: there simply was no later quartet composer capable of having it oth ways as consistently and as variedly... So far as the art - as distinct from the craft - of string quartet writing is concerned he was not only the first but actually turned what seemed an unpromising medium into what was to become the most expressive form of Western instrumental composition. By Keller's estimate about 45 of Haydn's quaters - those discussed here are absolutely flwless consistently original master quartets, each a violent multidimensional contrast to any of the others.