Thanks for all the responses. They've given me much to think about.
Namaste: It was like a possession. It was someone singing through me but it wasn't unwelcome, just odd.
Starseeker: The girl, the music, the singing, the entire dream is not typical for me. It stands out from the rest and the girl, whoever she was, the memory of her was like a name on the tip of my tongue.
mu: The overall pleasantness of that dream is what makes it stand out so vividly from my other dreams that week. I wish I could get back to that state of mind.
Burned up: I'd like to meet her too, anyone who can inspire me to erupt into spontaneous poetry and song MUST be met.
Lucidbulbs: I smile too thinking about that dream, for various reasons. It's very rare that the memory of a dream (or any memory for that matter) can make me smile with such immaculate affinity.