For some reason, my favorite pictures usually end up being ones that I can only find in ****ty, tiny resolutions. Some exceptions below, but it's a tendency for sure.
Above is one of my favorite groups; Madredeus. I love this band. The pictures above fit the feel of their music exceedingly well, I think.
The above is a great picture of their singer, Teresa Salgueiro, who's also released some good solo albums.
Above: Judie Tzuke, Rickie Lee Jones, Joni Mitchell.
And finally, Alanis Morisette. I'm not the biggest fan, but I like some of her music well enough, and probably more than most people on these boards. In any case, she always had a really interesting look to her.