Arriving as a teenager in the thirties, she remained the only vocalist to star in the Swing Era, make the leap to bebop’s wild embrace, and then, in the fifties, secure a new position as the ultimate medium for the American popular song. Her near three-octave range combined with her flawless technique and instinctive musicianship to make her a wonderful interpreter— able to perfectly run down a lead sheet— and at the same time one of the signal improvising musicians in recorded history. And who can name a more consistently satisfying singer? Sarah Vaughan’s velvety swoops might elicit more swoons; Betty Carter’s audacious excursions might better command unbridled awe. But with her rhythmic authority, her commonsense reading of lyrics, her unexpected musical quotes, and her essential girlishness, no singer ever made listeners happier than Fitzgerald did.