Sara Groves is one of the my favorite singer/songwriters in music today. Here are a couple of YouTube selections. The video quality is marginal at best, but the song is always the thing. Transcendant lyrics, minimalistic arrangements, and a voice that is at once powerful and tender. All of her albums are excellent, and each has its own character.
First, a powerful song called "You Are The Sun" from her album, Add to the Beauty.
Second, "Something Changed," also from Add To The Beauty. This version is excerpted from the trailer to the new movie, "The Ultimate Gift".
Here is a live video version of "Something Changed," too, recorded at The Crystal Cathedral. It's slightly different and a little less polished, and her vocal is more fragile, but that is not a criticism. I like both versions.