Imogen Heap is my current favorite modern musician. I consider her the most interesting composer I have come across in a really long time and one of the most technologically adept female composers since Laurie Anderson.
Imogen Heap spent a year secluded in her apartment composing her album Speak For Yourself which brought her a Grammy nomination for Best New Artist in 2007 (an award she should have won, in my opinion). The songs on this album are rich with layers of sound that she is amazingly able to recreate in concert using synthesizers and other devices. Her voice has an incredible range of nearly three octaves.
Her song Hide And Seek (#66), which appeared on a compilation album of songs of Grammy nominees, was my first experience of her music and an immediate favorite. Here she performs this song live:
I like nearly every song on the Speak For Yourself album, but one that I like the best is one called Have You Got It In You (#67). Unfortunately, there does not yet exist in YouTube a live version of this song that isn't mangled in some way, so here is a rather boring to look at, but at least beautiful to listen to version from her album: