What is Prayer?

This was our first topic. I've been thinking about it a lot lately.
There have been so many times in life where I felt connected to something outside myself, where I had that "spiritual experience" of love, peace, and/or an answer.

This came in many ways. Sometimes, it was through what I had been traditionally taught was prayer. Sometimes through meditation. Sometimes through yoga practice, or piano practice, or singing in a great choir, or listening to a great choir, or creating any art, or experiencing someone else's art, often through nature and being surrounded by people I love.

I was discussing the empty, nothing feeling that I get when I seek for this feeling and can't find it easily. "How is God speaking to you?" A friend asked. At that time in my life, I was getting nothing from the structure of prayer I had been taught. But I was getting everything through art. Yes, God was speaking to me through art.

But then, my concept of what/who God even is was thrown into great questioning, and the feeling of "God speaking to me" has been ever more elusive.

So what is this prayer thing anyway?
Is that feeling of being spoken to something that stems from within us? A belief system we create so much so that it becomes reality?
Or is it something that truly comes from someone/something else; external?

Thus began our first discussion.