I have once. It was really weird. I was dreaming that i was dreaming that i was a composer (composing singers lol) and had several singers singing on stage. after the dream was over, I woke up at my friends house and my friend was talking about how he had a dream were i composed a few singers and I said "You had the same dream I did?" he replied yes and told his cousin about it. Then I thought to myself, you know what, Im probably still dreaming but never went lucid. It was real weird.