During the course of his career, Pleis worked with many artists, including Louis Armstrong, Harry Belafonte, Bing Crosby, Sammy Davis Jr., Benny Goodman, Earl Grant, Brenda Lee, and Joe Williams.

He was one of Jan Savitt's Top Hatters,[6] playing piano and doing arrangements,[7] a position he left in 1942 to enlist in the Army during World War II.

[11] Pleis was also part of the Dixieland All-Stars group[12] which backed Brewer's breakout hit (and signature song) "Music!

[18] In early May 1950, he accompanied his future wife, London recording artist Eve Young, on a promotional tour prior to her opening show.

[22] In June 1950, Pleis married Eve Young,[23][24] and the March birth of their daughter Michelle was noted in an April 1951 Billboard.

[30] Her debut for Coral, backed by Pleis' orchestra, was the song "Hold Me, Thrill Me, Kiss Me," and it became an enormous hit.

[33] 1954 saw the release of the orchestra's Decca singles, "Frenchman in St. Louis"/"Pagan in Paris",[34] "Ah Ri Rung",[35] and "For Always"/"Beyond the Blue Horizon",[36] and the orchestra backed the Dinning Sisters on "Steel Guitar Rag",[37] Eileen Barton on "And Then",[38] and Teresa Brewer on her album A Bouquet of Hits.

[49] 1957 saw the release of singles "(But As They Say) That's Life"/"Goodnight Waltz",[50] "Search for Paradise"/"Serenade to Michelle",[51] and "The Carefree Heart"/"Serenade in Soft Shoe",[52] and the Orchestra backed Georgie Shaw on "One More Sunrise", Sammy Davis Jr. on "The Golden Key",[53] and Merv Griffin on "I'll Be Thinking of You".

[60] Pleis and Orchestra backed Sammy Davis Jr. on a dozen tracks for Decca, including "What Kind of Fool Am I?"

(which won the Grammy Award for Song of the Year in 1963), "The Lady Is a Tramp", "I Gotta Right to Sing the Blues", "Do Nothin' Till You Hear From Me", "I Got a Woman", "There Is No Greater Love", "Gee, Baby, Ain't I Good to You", "This Little Girl of Mine", "Till Then", and "Mess Around".

[66] Pleis and His Orchestra performed the songs "Strange Feelings" and "The Blues I Got Comin' Tomorrow" for the soundtrack of the 1961 film, Force of Impulse.

[1] Pleis arranged the songs on side one of Johnny Hartman's 1967 album, I Love Everybody, including "If I Had You", "I Cover the Waterfront", and "For Once in My Life".

[69] Under the moniker The Sounds of Our Times, Pleis co-produced and penned two songs for the 1967 easy listening, psychedelic instrumental LP Music of the Flower Children.