I have this sometimes-fantasy about being a backup singer. Usually this fantasy rolls around when the radio is on. I could never actually be a backup singer, and I don't truly want to be one. It's just one of those occassional dreams, like when I fantasize about telling my boss something I would not ever actually tell her or when I create imaginary scenarios in my head (they're usually quite dramatic) and work myself up to the point where I'm on the verge of tears and need to bring myself back to reality.
When I think of my tendency to fantasize, it reminds me of one of my grade-school teacher's comments on my report card - "MOAM has a tendency to daydream." I'd often bust out pencil and paper, start doodling, and then, completely unconsciously, start humming loudly.