Two days before my grandma died I had this dream these old when where picking berries in a field, they were all dressed in black dresses with white collars. One of them stopped, looked up and said "ooh honey they are playing my song" one of there other women looked at her and said "what are you talking about, there's no music playing. This old woman the one who heard music stepped on of the field onto a path, started walking and disappeared. Two days later my grandma died of a stroke. Thing was I woke up crying cause I the old woman was her. How do I know people are going to die and how can I make it go away?

This sounds like a one of premonition rather than anything more involved and worrisome.
Dreams can do odd things especially when you are concerned or worrying about someone or something...
The mind just goes into overtime.

It happened one time to your grandmother, and does not mean you will ever have that again. Sometimes for those we love, and are close to, we seem to know.

Everyone dies. Old people die a lot more than not die. Therefore your grandmother was going to die, and not only that, but many old people sense when they don't have much time left. You picked up on the little ways she knew.

You were obviously very close to your grandma which is why this dream happened.One could almost say that she was trying to forwarn you... who knows... clearly like my own mother she new her time was short.I think she was happy to go referring to the fact that " they were playing her song" which left her to follow the music in a joyful way,so please don't be sad or fearful she will always be withyou.