5 - Audrey Hepburn. Not known for her singing, clearly, her inclusion here is due entirely to her rendition of Moon River in Breakfast at Tiffany's, which warms not just the cockles of my heart, but many other hard to reach parts as well.
4 - Roberta Flack. A relatively recent discovery for me, I found the above album in a thrift store in Brooklyn ($3!!) and bought it as much for the cover as for the fact that she's the "Killing Me Softly" lady. Full of gospel-tinged tunes and subtle arrangements, it totally blew me away.
3 - Joni Mitchell. Where would I be without Joni? Possibly the finest songwriter and certainly the best lyricist of her generation (and who's been better since?), she has the kind of voice to either scare you or excite you. Sometimes low and smokey, other times up in the stratosphere, she's always on target and never boring. Her style is often conversational and she does make you think she's telling you all this down the pub a lot of the time. I can't really believe she's only at 3, but...
2 - Ella Fitzgerald. This lady could sing the phone book and it would sound good. As musically perfect as anyone can be, her scats and improvised lines have to be heard repeatedly to be believed. She recorded pretty much everything in her long life, but you can't go wrong with her interpretations of either Duke Ellington or George Gershwin. The one above probably ain't bad, either.
1 - Aretha Franklin. The Queen of Soul, the best there is. I saw a clip a few years ago of one of those terrible VH-1 Diva events, with Mariah Carey and Alicia Keys and other wailing eejits giving it large, and on walked Aretha, in her 50s and the size of a small house, and in about 10 seconds had floored them all. Not with power, not with pitch, but with phrasing, craft, and the fact that she doesn't need to have big hair (and the rest) or appear nude on the front of Rolling Stone to sell records. I love her gospel albums even though I hate religion, and her version of Bridge Over Troubled Water is the best yet, but I'd recommend Aretha Sings the Blues - the first track, Drinking Again, will have you reaching for the spirits before she's finished the first verse. Which is a good thing.
And as Ford says, an honourable mention to Liz Fraser. Although she could have tried just a bit harder to make sense, if you ask me. Really. (tuts).