Tristano was born in Chicago on March 19, 1919. His mother, Rose Tristano (nee Malano), was also born in Chicago. His father, Michael Joseph Tristano, was born in Italy and moved to the United States as a child. Lennie was the second of four brothers.

In Ind's view, Tristano "was always so gentle, so charming and so quietly spoken that his directness could be unnerving." This directness was noted by others, including bassist Chubby Jackson, who commented that Tristano had almost no tact and would not worry about being rude or making others feel incompetent. Some of his students described Tristano as domineering, but others indicated that this impression came from his demanding discipline in training and attitude to music.  Writer Barry Ulanov commented in 1946 that Tristano "was not content merely to feel something, [...] he had to explore ideas, to experience them, to think them through carefully, thoroughly, logically until he could fully grasp them and then hold on to them." Tristano criticized the free jazz that began in the 1960s for its lack of musical logic as well as its expression of negative emotions. "If you feel angry with somebody you hit him on the nose - not try to play angry music", he commented; "Express all that is positive. Beauty is a positive thing." He expanded on this by distinguishing emotion from feeling, and suggested that playing a particular emotion was egotistical and lacking in feeling.  Tristano also complained about the commercialization of jazz and what he perceived to be the requirement to abandon the artistic part of playing in order to earn a living from performing. Later commentators have suggested that these complaints ignored the freedom that he was given by Atlantic and blamed others for what in many cases were the outcomes of his own career decisions.

Answer the following question by taking a quote from the article: What did the eople he taught say
Some of his students described Tristano as domineering, but others indicated that this impression came from his demanding discipline in training and attitude to music.