Answer by taking a quote from the following article:

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.

Tristano's second album for Atlantic was recorded in 1961 and released the following year. The New Tristano, as was stressed on the album cover, consisted entirely of piano solos and no overdubbing or tape-speed manipulation was employed. The tracks contain left-hand bass lines that provide structure to each performance as well as counterpoint for the right-hand playing; block chords, unclear harmonies and contrasting rhythms also appear. Other solo piano recordings that Tristano made in 1961 were not released until the 1970s.  Tristano and his wife formally divorced in 1962. Their son, Steve, who was born in 1952, met his father only once after their initial 1956 separation. Tristano married again in the early 1960s. His second wife was Carol Miller, one of his students. They had a son, Bud, and two daughters, Tania and Carol. The couple divorced in 1964, and Tristano later lost a custody battle with his ex-wife over the children.  In 1964 the pianist reformed his quintet with Konitz and Marsh for a two-month engagement at the Half Note and more performances in Canada. The quartet, missing Konitz, played in Toronto again in the following year. Tristano played on occasion at the Half Note Club until the mid-1960s, and toured Europe in 1965. His European tour was mainly as a solo pianist, and the playing was in the style of his The New Tristano recordings. He performed with Ind and others in concerts in the UK in 1968; they were well received, and Tristano returned the following year. His last public performance in the US was in 1968.  Tristano declined offers to perform in the 1970s; he explained that he did not like to travel, and that the requirement for a career-minded musician to play concerts was not something that he wanted to follow. He continued teaching, and helped to organize concerts for some of his students. Another album, Descent into the Maelstrom, was released in the 1970s; it consisted of recordings made between 1951 and 1966.  Tristano had a series of illnesses in the 1970s, including eye pain and emphysema (he smoked for most of his life). On November 18, 1978 he died of a heart attack at home in Jamaica, New York.

What was the first thing he did according to the article
Tristano's second album for Atlantic was recorded in 1961 and released the following year.