William John Evans ( , August 16, 1929 - September 15, 1980) was an American jazz pianist and composer who mostly worked in a trio setting. Evans' use of impressionist harmony, inventive interpretation of traditional jazz repertoire, block chords, and trademark rhythmically independent, "singing" melodic lines continue to influence jazz pianists today. Born in Plainfield, New Jersey, in 1929, he was classically trained, and studied at Southeastern Louisiana University and the Mannes School of Music, where he majored in composition and received the Artist Diploma. In 1955, he moved to New York City, where he worked with bandleader and theorist George Russell.

Evans' career began just before the rock explosion in the 1960s. During this decade, jazz was swept in a corner, and most new talents had few opportunities to gain recognition, especially in America. However, Evans believed he had been lucky to gain some exposure before this profound change in the music world, and never had problems finding employers and recording opportunities.  Evans never embraced new music movements; he kept his style intact. For example, he lamented watching Davis shift his style towards jazz fusion, and blamed the change on considerations of commerce. Evans commented "I would like to hear more of the consummate melodic master [Davis], but I feel that big business and his record company have had a corrupting influence on his material. The rock and pop thing certainly draws a wider audience. It happens more and more these days, that unqualified people with executive positions try to tell musicians what is good and what is bad music." However, Evans and Davis kept in touch throughout their lives.  While Evans considered himself an acoustic pianist, from the 1970 album From Left to Right on, he also released some material with Fender-Rhodes piano intermissions. However, unlike other jazz players (e.g. Herbie Hancock) he never fully embraced the new instrument, and invariably ended up returning to the acoustic sound. "I don't think too much about the electronic thing, except that it's kind of fun to have it as an alternate voice. (...) [It's] merely an alternate keyboard instrument, that offers a certain kind of sound that's appropriate sometimes. I find that it's a refreshing auxiliary to the piano--but I don't need it (...) I don't enjoy spending a lot of time with the electric piano. I play it for a period of time, then I quickly tire of it, and I want to get back to the acoustic piano." He commented that electronic music: "just doesn't attract me. I'm of a certain period, a certain evolution. I hear music differently. For me, comparing electric bass to acoustic bass is sacrilege."

How was he influenced by this?
Evans believed he had been lucky to gain some exposure before this profound change in the music world, and never had problems finding employers and recording opportunities.