Cello Fury and Project Trio offer a new spin to the standard chamber ensemble. Cello Fury consists of three cellists and a drummer and Project Trio includes a flutist, bassist, and cellist. Several groups such as Classical Revolution and Simple Measures have taken classical chamber music out of the concert hall and into the streets. Simple Measures, a group of chamber musicians in Seattle (Washington, USA), gives concerts in shopping centers, coffee shops, and streetcars. The Providence (Rhode Island, USA) String Quartet has started the "Storefront Strings" program, offering impromptu concerts and lessons out of a storefront in one of Providence's poorer neighborhoods. "What really makes this for me", said Rajan Krishnaswami, cellist and founder of Simple Measures, "is the audience reaction ... you really get that audience feedback." Chamber music performance is a specialized field, and requires a number of skills not normally required for the performance of symphonic or solo music. Many performers and authors have written about the specialized techniques required for a successful chamber musician. Chamber music playing, writes M. D. Herter Norton, requires that "individuals ... make a unified whole yet remain individuals. The soloist is a whole unto himself, and in the orchestra individuality is lost in numbers ...". Many performers contend that the intimate nature of chamber music playing requires certain personality traits. David Waterman, cellist of the Endellion Quartet, writes that the chamber musician "needs to balance assertiveness and flexibility." Good rapport is essential. Arnold Steinhardt, first violinist of the Guarneri Quartet, notes that many professional quartets suffer from frequent turnover of players. "Many musicians cannot take the strain of going "mano a mano" with the same three people year after year." Mary Norton, a violinist who studied quartet playing with the Kneisel Quartet at the beginning of the last century, goes so far that players of different parts in a quartet have different personality traits. "By tradition the first violin is the leader" but "this does not mean a relentless predominance." The second violinist "is a little everybody's servant." "The artistic contribution of each member will be measured by his skill in asserting or subduing that individuality which he must possess to be at all interesting." "For an individual, the problems of interpretation are challenging enough", writes Waterman, "but for a quartet grappling with some of the most profound, intimate and heartfelt compositions in the music literature, the communal nature of decision-making is often more testing than the decisions themselves."