Her voice was a mezzo-soprano of unusual range and color. Its most distinctive quality was not technical, though she had excellent technique — her breath control, her phrasing, her ability to sustain a note at the end of a phrase with controlled diminuendo were skills that she had developed over decades. The most distinctive quality was something harder to describe: a quality of emotional directness, of meaning what the song said at the moment of singing it, that connected with listeners at a level that felt personal rather than theatrical.
“She was the best singer I ever heard,” Fred Astaire told an interviewer in the mid-1970s, declining to be more specific than that. The statement captures something that most of the musicians who worked with her expressed in various forms: that there was something in what she did that operated beyond technique, that her musical intelligence and her instinctive connection to the emotional content of a song produced a kind of performance that others could admire but not replicate.
Her vocal quality changed over the decades, as all voices do and as her health made inevitable. The full-spectrum power of her MGM years, the absolute command of “The Man That Got Away” in A Star Is Born, the sustained extraordinary performance of the Carnegie Hall concert at thirty-eight — these are different realizations of the same fundamental instrument under different conditions. The later years brought loss as well as gain: some of the upper register that had been brilliant in her twenties was less reliable in her forties, and the effects of decades of pharmaceutical management on her physical stamina were audible in performances that varied significantly with her physical state on a given night.