I can't think of any discussion where the subject of Greatest Singers comes up where Sarah Vaughan doesn't figure prominently in the equation. Certainly in the area of Jazz Singers Vaughan is one of the top five. I can't think of anyone who has come close to her in recent years - not that I'm one of those people who is absorbed with all things past being better, but Sarah Vaughan had a point of view and a tone and a style of singing that just hasn't been duplicated. She was, and still is, unique and probably always will be.
Here is a short set she did as part of the NBC Radio series Stars Of Jazz broadcast on August 21, 1952. It features Vaughan in a relaxed club setting during a time when her career was skyrocketing.
Unfortunately, time runs out just as she's getting into a groove and that's a shame. But it's classic Sarah Vaughan, and if you aren't familiar with her, here's a good place to start.