Critics and colleagues praised his ability to color the tone on every word, giving his singing an unusual range of expressive shadings that made even simple phrases sound psychologically rich. Contemporary accounts state that his vocal acting was revolutionary for its time: he did not just “pose” on stage, but fused vocal line, diction, and physical movement into a single, believable character. In roles like Boris Godunov and Mephistopheles, he shaped dynamics, timbre, and phrasing to mirror a character’s inner turmoil, setting a new standard for naturalistic operatic acting. This complete integration of voice and drama led many in the 20th century to regard him as the greatest “singing actor” among basses, and his recordings are still cited as models of operatic characterization.