Described by critic Scott Yanow as "the definitive swing pianist",[2] Wilson's piano style was gentle, elegant, and virtuosic.

[4] His work was featured on the records of many of the biggest names in jazz, including Louis Armstrong, Lena Horne, Benny Goodman, Billie Holiday, and Ella Fitzgerald.

[6] In 1935, while jamming with Benny Goodman and Carl Bellinger at a house party held by Mildred Bailey, they caught the attention of producer John Hammond, who arranged several recording sessions for them.

During these years, he also took part in many sessions with swing musicians such as Lester Young, Roy Eldridge, Charlie Shavers, Red Norvo, Buck Clayton, and Ben Webster.

[8] In the mid to the late 1940s, Wilson mainly focused on studio recordings, on-screen performances, and radio broadcasts, instead of playing on public stages.

[11] He was dubbed the "Marxist Mozart" by Howard "Stretch" Johnson due to his support for left-wing causes: he performed in benefit concerts for The New Masses journal and for Russian War Relief, and he chaired the Artists' Committee to elect Benjamin J. Davis (a New York City council member running on the Communist Party USA ballot line).

[16] According to Wilson, he was first exposed to jazz by listening to the music of Duke Ellington, Earl Hines, Louis Armstrong, and Fats Waller.

His fluid runs and gracefully relaxed rhythmic coordination with clean and even phrasing might have been reflected by his reserved personality and his experience with Benny Goodman under racial segregation.

[20] Though he played with a lot of bebop musicians such as Charlie Parker and Dizzy Gillespie during his work as a sideman, he held on to swing vocabulary based on chord tone arpeggios and diatonic harmony.

[21] His playing on "Congo Blues"[22] for Red Norvo and His Sextet in 1945, for examples, demonstrates the stylistic contrast between Wilson and Dizzy Gillespie and Charlie Parker.

[21] Wilson's style went on to influence other pianists such as his contemporary Mary Lou Williams,[23] Mel Powell, Billy Kyle, Jess Stacy, and Joe Bushkin.