Pianist, composer, arranger and conductor. Began with the orchestra of Abe Lyman.
He produced Hugo Montenegro's album, Colours Of Love (1970).
By 1948, Pleis was working at the RCA Victor studios on 24th Street, appearing on the cover of the January 1, 1949 issue of Billboard playing piano at the studio's holiday party.
His surname is pronounced "Pleece" (to rhyme with "fleece").
In New York, Pleis became successful as a pianist, arranger, conductor, and composer. He was one of Jan Savitt's Top Hatters, playing piano and doing arrangements, a position he left in 1942 to enlist in the Army during World War II.