Interesting. I really do find that music influences my dream content. I can't make a general rule, but I remember many times hearing a song in a dream only to wake and see it playing beside my bed...maybe there's potential. I find that relaxing, slow music that picks up towards the end is best..., but I go for more rythym than less...my mind seems to get excited by it as I sleep and may very well produce some interesting dreams...but then again, maybe not...