Who is the vocalist on the classic rendition of Ellington's "A Train?"?

Back in the days of vinyl, I used to have an album with a title very similar to "Duke Ellington's Greatest Hits." On that album was only one version of each of the many different tunes Ellington performed in his great career. For "Take the A Train" the compiler chose a version that featured a vocal by a female singer with a great voice who broke into (what the liner notes described as) a "sexy scat" halfway through. I have long since lost the album, and lost track of that particular version of the song until I heard it on the radio today. I called, but the radio station was unable to tell me who the exact personnel on that track were. Can anyone out there help? Thanks.