I've had quite a few few occurrences of this, as I'm sure some of you also have. Basically, I'm talking about when you dream is affected by something that is happening in the real world simultaneously.

For instance, in a non-lucid dream I had, I had these stomach pains that were pretty bad, but I woke up and it turned that I had indigestion.

For an even better example, I was non-lucidly dreaming that I was at some place with a bunch of my friends, and one of them started barking like a dog, but I woke up a few seconds later, realizing that it was my actual dog who was barking.

But the question is, can we use this to our advantage? I was thinking, if we had like, a specific song or something set to go off right at the best time to be lucid, and you had it set it in your mind that this would be your dreamsign, so you would be able to hear the song while dreaming and easily become lucid! Would this work? Has anyone tried this before?